Initial for docs and gh-pages

Added the following docs:
- README.md as index page;
- CONTRIBUTING.md as the contribution guide;
- COPYING file from kernel source;
- CREDITS.md as the credits-file;
- MAILLIST.md as the mailing list info page;
- os.md as the index page of Alibaba Cloud Linux OS.

And also initialized for github pages, cayman is the theme we have
chosen.
Signed-off-by: NCaspar Zhang <caspar@linux.alibaba.com>

CONTRIBUTING.md

+Contributing to Alibaba Cloud Linux Kernel
+==========================================
+
+Table of Contents
+-----------------
+1. [Report bugs](#1-report-bugs)
+   1. [Report security issues](#11-report-security-issues)
+   2. [Report crash issues](#12-report-crash-issues)
+   3. [Report general issues](#13-report-general-issues)
+   4. [Report Alibaba Cloud Linux OS issues](#14-report-alibaba-cloud-linux-os-issues)
+2. [Help to improve](#2-help-to-improve)
+   1. [Get kernel source](#21-get-kernel-source)
+   2. [Build kernel](#22-build-kernel)
+   3. [Propose a patch](#23-propose-a-patch)
+
+-----------------
+
+## 1. Report Bugs
+
+The easiest way to participate in contributing to the project is just use ALK and Alibaba Cloud Linux OS, then report bugs to us. However, there are some ground rules against special types of bugs when filing a bug.
+
+### 1.1 Report security issues
+
+We welcome reports from security researchers and experts about possible security vulnerabilities with our kernel and operating system, however we discourage anyone to spread security issue details. To report a security issue, please send a private email to [alicloud-linux-os@service.alibaba.com](mailto:alibaba-linux-os@service.alibaba.com), we do appreciate it and will review it carefully at one.
+
+### 1.2 Report crash issues
+
+Kernel panic and system crash is critical to any users, we would raise priority against such bug reports, please file bug reports in our project [issues](https://github.com/alibaba/cloud-kernel/issues) page, in order to get better understanding of your problem, please include the following information as much as possible:
+
++ Kdump core or kernel stack trace when crashed;
++ Suspicious applications or operations that trigger the crash;
++ Kernel version if kdump core or full kernel stack trace not provided.
+
+Digging into a crash issue is always a difficult thing, we do thank to anyone who is willing to help with reproducing the crashes.
+
+### 1.3 Report general issues
+
+Feel free to file bug reports in our project [issues](https://github.com/alibaba/cloud-kernel/issues) page.
+
+### 1.4 Report Alibaba Cloud Linux OS issues
+
+ALK has tight connections with Alibaba Cloud Linux OS, if you run into any Alibaba Cloud Linux OS problems, feel free to file a bug report in our project [issues](https://github.com/alibaba/cloud-kernel/issues) page as well, or start a thread in [mailing lists](MAILLIST.md) or in [Alibaba Cloud Developer forum](https://bbs.aliyun.com/thread/450.html).
+
+## 2. Help to improve
+
+### 2.1 Get kernel source
+
+Before you decide to involve in kernel development, you need to get kernel source and build it. You can download a stable release source from [Releases](https://github.com/alibaba/cloud-kernel/releases) page, then extract the source to a directory:
+
+```shell
+tar xzf alk-release-7.tar.gz
+```
+
+Alternatively, you can use Git to clone from our git repo.
+
+```shell
+git clone git@github.com:alibaba/cloud-kernel.git
+cd cloud-kernel
+```
+
+> You may have noticed that `master` is not the default branch, instead, you would get a branch named like `alk-4.19.y`. This is due to our 'rebase' approach, every time we rebase from an LTS version, a new branch will be created and then be used as the default branch.
+
+### 2.2 Build kernel
+
+Before building the kernel, you will need a kernel config file. Here we provide a [default kernel config](config-4.19.y-x86_64) in `master` branch, just fetch it and rename to `.config`, then copy it to the top of kernel source directory.
+
+```bash
+wget https://raw.githubusercontent.com/alibaba/cloud-kernel/master/config-4.19.y-x86_64
+cp config-4.19.y-x86_64 cloud-kernel/.config
+```
+
+> The default kernel config is a simplified and customized version, which cuts numerous driver modules, like storage drivers, network drivers, etc. Hence, you should not run the kernel directly on a physical machine, otherwise the system would probably fail to boot. It is recommended that you run the kernel in KVM guests only, unless you are pretty sure required kernel drivers have enabled in your config.
+
+Now you can start your build, presuming you have already installed all required toolchains, then execute:
+
+```bash
+cd cloud-kernel
+make oldconfig
+make -jN # N normally refers to the CPU core numbers on the system
+make modules -jN
+sudo make modules_install
+sudo make install
+```
+
+Next, you can just reboot and run into the new kernel. Please make sure you have an emergency boot method deployed in case that the kernel fails to boot.
+
+### 2.3 Propose a patch
+
+During your daily using of ALK, you might have found some bugs and you are managed to find a way to fix it. So you probably want to propose a patch to us.
+
+You can follow the [submitting patches guide from kernel.org](https://www.kernel.org/doc/html/latest/process/submitting-patches.html), when your code is ready, you can just subscribe to our [developer's mailing list](MAILLIST.md#alibaba-cloud-linux-os-kernel-developers-group) and send the patch to us.

COPYING

+The Linux Kernel is provided under:
+
+	SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note
+
+Being under the terms of the GNU General Public License version 2 only,
+according with:
+
+	LICENSES/preferred/GPL-2.0
+
+With an explicit syscall exception, as stated at:
+
+	LICENSES/exceptions/Linux-syscall-note
+
+In addition, other licenses may also apply. Please see:
+
+	Documentation/process/license-rules.rst
+
+for more details.

CREDITS.md

+CREDITS
+=======
+
+> This is a credits-file of people that have contributed to Alibaba
+> Cloud Linux OS project and Alibaba Cloud Linux Kernel project.
+> The list is sorted by name. The fields are: name (N), email (E),
+> web-address (W) and description (D).
+
+----------------------------
+
+```
+N: Aliyun CLI developer team
+W: https://github.com/aliyun/aliyun-cli
+D: Universal Command Line Interface for Alibaba Cloud
+```

MAILLIST.md

+Mailing Lists
+=============
+
+## Alibaba Cloud OS & Kernel User Group
+
++ Click to [Subscribe](mailto:alibabacloud-linux-users+subscribe@googlegroups.com?subject=subscribe);
++ Click to [Unsubscribe](mailto:alibabacloud-linux-users+unsubscribe@googlegroups.com?subject=subscribe);
++ Start a thread in the mailing list by writing an E-mail to: [alibabacloud-linux-users@googlegroups.com](mailto:alibabacloud-linux-users@googlegroups.com)
+
+## Alibaba Cloud OS & Kernel Developers Group
+
++ Click to [Subscribe](mailto:alibabacloud-linux-dev+subscribe@googlegroups.com?subject=subscribe);
++ Click to [Unsubscribe](mailto:alibabacloud-linux-dev+unsubscribe@googlegroups.com?subject=subscribe);
++ Start a thread in the mailing list by writing an E-mail to: [alibabacloud-linux-dev@googlegroups.com](mailto:alibabacloud-linux-dev@googlegroups.com)

README.md

+Alibaba Cloud Linux Kernel
+==========================
+
+Table of Contents
+-----------------
+1. [What is Alibaba Cloud Linux Kernel](#1-what-is-alibaba-cloud-linux-kernel)
+2. [Getting Started](#2-getting-started)
+   1. [Run with pre-built RPMs (recommended)](#21-run-with-pre-built-rpms-recommended)
+   2. [Compile from source](#22-compile-from-source)
+3. [Contributing](#3-contributing)
+4. [Credits](#4-credits)
+5. [License](#5-license)
+6. [Contact Us](#6-contact-us)
+
+---------------------------------
+
+
+## 1. What is Alibaba Cloud Linux Kernel
+
+Alibaba Cloud Linux Kernel (ALK), a customized and optimized version of Linux kernel, is originated by Alibaba Operating System Team (formerly known as Taobao Kernel Team). ALK is installed as the default kernel in Alibaba Cloud Linux OS version 2 (a.k.a Aliyun Linux 2), which is running on Alibaba Cloud Elastic Compute Service (ECS) product. In ALK, several features and enhancements adapted to specific Alibaba Cloud infrastructre and products have been made to help Alibaba Cloud customers to achieve better user experiences.
+
+Like many other kernels, ALK should work with almost all commonly-used Linux distributions, however, we highly recommend you run it in Alibaba Cloud Linux OS with Alibaba Cloud ECS instances to get best functionality, performance and stability.
+
+To get more information about Alibaba Cloud Linux OS, please refer to [this](os.md) link.
+
+## 2. Getting Started
+
+To use ALK, you may want either to run a pre-built version or to compile it from source codes. Note that the default kernel configuration file is a customized version for Alibaba Cloud ECS instances, you might need to enable specific drivers and re-compile the kernel if you want to run it on non-ECS platforms.
+
+### 2.1 Run with pre-built RPMs (recommended)
+
+Installing from YUM source repo is the most recommended way:
+
++ Step 1: Create a new YUM repo file:
+
+```shell
+sudo vim /etc/yum.repos.d/alinux-2.1903-plus.repo
+```
+
++ Step 2: Fill repository information into the repo file:
+
+```shell
+[plus]
+name=Alibaba Cloud Linux 2.1903 Plus Software Collections
+baseurl=http://mirrors.aliyun.com/alinux/2.1903/plus/x86_64/
+enabled=1
+gpgcheck=1
+gpgkey=http://mirrors.aliyun.com/alinux/RPM-GPG-KEY-ALIYUN
+```
+
++ Step 3: Install the kernel:
+
+```shell
+sudo yum install -y kernel kernel-devel kernel-headers
+```
+
++ Step 4: Reboot system and enjoy ALK.
+
+### 2.2 Compile from source
+
++ Step 1: Fetch kernel source:
+  + Download from [Releases](https://github.com/alibaba/cloud-kernel/releases) page for a stable release and extract the source;
+  + Or clone from the project repo: `git clone git@github.com:alibaba/cloud-kernel.git`.
+
++ Step 2: Fetch a [default kernel config](config-4.19.y-x86_64) from `master` branch and rename it to `.config`, then copy it to the top of kernel source directory;
+
++ Step 3: Compile and install kernel via the following commands:
+
+```shell
+make oldconfig
+make -jN # N normally refers to the CPU core numbers on the system
+make modules -jN
+sudo make modules_install
+sudo make install
+```
+
++ Step 4: Reboot system and enjoy ALK.
+
+## 3. Contributing
+
+There are different ways to contribute to ALK project, please read [CONTRIBUTING](CONTRIBUTING.md) file to get more details.
+
+## 4. Credits
+
+A full list of contributors from teams and individuals inside and out of Alibaba Group could be found in [CREDITS](CREDITS.md) file. And special thanks would be given to:
++ [CentOS project](https://www.centos.org/);
++ [Clear Linux project](https://clearlinux.org/);
++ [Intel 0-Day (LKP) project](https://01.org/lkp);
++ [Kata Containers project](https://katacontainers.io/);
++ [Linux kernel project](https://www.kernel.org/).
+
+## 5. License
+
+We use the same license as the upstream does, so please refer to the [COPYING](COPYING) file.
+
+## 6. Contact Us
+
++ Join the [mailing list discussions](MAILLIST.md);
++ Join the [forum discussions](https://bbs.aliyun.com/thread/450.html);
++ Send us an E-mail to [alicloud-linux-os@service.alibaba.com](mailto:alicloud-linux-os@service.alibaba.com) is always a good idea.

_config.yml

+theme: jekyll-theme-cayman
+show_downloads: false
+include:
+- CONTRIBUTING.md
+- COPYING

_layouts/default.html

+<!DOCTYPE html>
+<html lang="{{ site.lang | default: "en-US" }}">
+  <head>
+
+    {% if site.google_analytics %}
+      <script async src="https://www.googletagmanager.com/gtag/js?id={{ site.google_analytics }}"></script>
+      <script>
+        window.dataLayer = window.dataLayer || [];
+        function gtag(){dataLayer.push(arguments);}
+        gtag('js', new Date());
+        gtag('config', '{{ site.google_analytics }}');
+      </script>
+    {% endif %}
+    <meta charset="UTF-8">
+
+{% seo %}
+    <meta name="viewport" content="width=device-width, initial-scale=1">
+    <meta name="theme-color" content="#157878">
+    <meta name="apple-mobile-web-app-status-bar-style" content="black-translucent">
+    <link rel="stylesheet" href="{{ '/assets/css/style.css?v=' | append: site.github.build_revision | relative_url }}">
+  </head>
+  <body>
+    <header class="page-header" role="banner">
+      <h1 class="project-name">{{ page.title | default: site.title | default: site.github.repository_name }}</h1>
+      <h2 class="project-tagline">{{ page.description | default: site.description | default: site.github.project_tagline }}</h2>
+      {% if site.github.is_project_page %}
+        <a href="{{ site.github.repository_url }}" class="btn">View on GitHub</a>
+      {% endif %}
+      {% if site.show_downloads %}
+        <a href="{{ site.github.zip_url }}" class="btn">Download .zip</a>
+        <a href="{{ site.github.tar_url }}" class="btn">Download .tar.gz</a>
+      {% endif %}
+    </header>
+
+    <main id="content" class="main-content" role="main">
+      {{ content }}
+
+      <footer class="site-footer">
+        {% if site.github.is_project_page %}
+          <span class="site-footer-owner"><a href="{{ site.github.repository_url }}">{{ site.github.repository_name }}</a> is maintained by <a href="{{ site.github.owner_url }}">{{ site.github.owner_name }}</a>.</span>
+        {% endif %}
+        <span class="site-footer-credits">This page was generated by <a href="https://pages.github.com">GitHub Pages</a>.</span>
+      </footer>
+    </main>
+  </body>
+</html>

assets/css/style.scss

+---
+---
+
+$header-bg-color: #d95a00;
+$header-bg-color-secondary: #ff8126;
+$section-headings-color: #ff6a00;
+
+@import 'jekyll-theme-cayman';
+
+body {
+    font-family: "Univers 45 Light", "Helvetica Light", Helvetica, Arial, sans-serif;
+}
+
+h1, h2, h3, h4, h5, h6 {
+    font-family: "Univers IT std bold", "Helvetica Bold", Helvetica, Arial, sans-serif;
+}

os.md

+---
+title: Alibaba Cloud Linux OS
+description: An open-source Linux distribution powered by Alibaba Cloud
+---
+
+Brief Introduction to Alibaba Cloud Linux OS
+============================================
+
+Table of Contents
+-----------------
+1. [What is Alibaba Cloud Linux OS](#1-what-is-alibaba-cloud-linux-os)
+2. [How to use](#2-how-to-use)
+3. [Getting source](#3-getting-source)
+4. [Getting helps](#4-getting-helps)
+
+-------------------------
+
+## 1. What is Alibaba Cloud Linux OS
+
+Alibaba Cloud Linux (a.k.a. Aliyun Linux) OS is an open-source Linux distribution originated by Alibaba Operating System team, aiming to deliver OS services with various functionality, high performance and stability to Alibaba Cloud Elastic Compute Service (ECS) customers.
+
+Current released version is Alibaba Cloud Linux OS version 2, or known as 'Aliyun Linux 2'.
+
+## 2. How to use
+
+Simply buy an ECS instance and get started: [chs](https://ecs-buy.aliyun.com/), [eng](https://ecs-buy-intl.aliyun.com/).
+
+## 3. Getting source
+
+When running with an Alibaba Cloud Linux 2 OS, you should be able to fetch source RPMs via `yumdownloader` tool (make sure you have `yum-utils` package installed first):
+
+```bash
+sudo yum install -y yum-utils
+sudo yumdownloader --source <source package>
+```
+
+Meanwhile, you are free to fetch kernel source from [Alibaba Cloud Linux Kernel](https://github.com/alibaba/cloud-kernel) project.
+
+## 4. Getting Helps
+
+To get helps when using Alibaba Cloud Linux OS, you can
+
++ File a [ticket](https://selfservice.console.aliyun.com/ticket/createIndex) if you are an Alibaba Cloud ECS customer;
++ Join the [mailing list discussions](MAILLIST.md);
++ Join the [forum discussions](https://bbs.aliyun.com/thread/450.html);
++ Send us an E-mail to [alicloud-linux-os@service.alibaba.com](mailto:alicloud-linux-os@service.alibaba.com).