docs: Add engligh README

.github/FUNDING.yml

-# These are supported funding model platforms
-
-github: # Replace with up to 4 GitHub Sponsors-enabled usernames e.g., [user1, user2]
-patreon: # Replace with a single Patreon username
-open_collective: # Replace with a single Open Collective username
-ko_fi: # Replace with a single Ko-fi username
-tidelift: # Replace with a single Tidelift platform-name/package-name e.g., npm/babel
-community_bridge: # Replace with a single Community Bridge project-name e.g., cloud-foundry
-custom: # Replace with a single custom sponsorship URL

README.md

 <p align="center"><a href="https://liuyib.github.io/hexo-theme-stun/" target="_blank" rel="noopener noreferrer"><img width="100" src="https://raw.githubusercontent.com/liuyib/picBed/master/hexo-blog/20190603093757.png" alt="stun logo"></a></p>
 
-<h3 align="center">一个漂亮、简洁的 hexo 主题</h3>
+<h3 align="center">A beautiful & simple theme for Hexo</h3>
 
 <p align="center">
   <a href="http://commitizen.github.io/cz-cli/" target="_blank" rel="noopener noreferrer">
@@ -13,41 +13,45 @@
     <img alt="hexo" src="https://img.shields.io/badge/hexo-%3E%3D3.0-blue.svg?style=flat-square">
   </a>
   <a href="https://github.com/liuyib/hexo-theme-stun/releases" target="_blank" rel="noopener noreferrer">
-    <img alt="GitHub release" src="https://img.shields.io/github/release/liuyib/hexo-theme-stun.svg?style=flat-square">
+    <img alt="GitHub release" src="https://img.shields.io/github/release-pre/liuyib/hexo-theme-stun.svg?style=flat-square">
   </a>
 </p>
 
-## 演示
+[English](https://github.com/liuyib/hexo-theme-stun/blob/master/README.md) | [中文简体](https://github.com/liuyib/hexo-theme-stun/blob/master/README_zh_CN.md)
 
-- [蚂蚁的博客](https://liuyib.github.io/)
+## Demo
 
-如果你正在使用 stun 主题，并希望像上面一样，在这里展示出来，你可以通过 PR 将你的网站链接填写在这里。
+- [liuyib`s Blog](https://liuyib.github.io/)
 
-## 安装
+If you are using the stun theme and would like it to be shown here, you can fill in your website link by [PR](https://github.com/liuyib/hexo-theme-stun/pulls).
 
-- 安装 stun
+## Installation
 
-进入 hexo 根目录，执行指令。
+- Install stun
+
+Enter your hexo directory, run this.
 
 ``` bash
 git clone https://github.com/liuyib/hexo-theme-stun.git themes/stun
 ```
 
-- 如果你没有安装对 pug, stylus 的支持，还需执行指令
+- Install pug and stylus (optional)
+
+If you don't have pug and stylus renderer, run this.
 
 ``` bash
 npm install --save-dev hexo-render-pug hexo-renderer-stylus
 ```
 
-## 使用
+## How to use
 
-修改 hexo 根目录下的 `_config.yml` 文件。
+Modify the `_config.yml` file in your hexo root directory.
 
 ``` yml
 theme: stun
 ```
 
-## 更新
+## Update
 
 ``` bash
 cd themes/stun
@@ -55,9 +59,9 @@ cd themes/stun
 git pull
 ```
 
-## 配置
+## Configuration
 
-如果你不想麻烦，你只需要填写网站 favicon 和站点头像的路径即可完成最基本的配置。其他的配置项都是默认的。
+If you don't want to bother, you only need o fill the image path of the wetbsite favicon and your avatar to complete the most basic configuration. Other configuration items are default.
 
 ``` yml
 favicon: # url or path
@@ -65,12 +69,12 @@ favicon: # url or path
 avatar: # url or path
 ```
 
-详细配置，请访问：[https://liuyib.github.io/hexo-theme-stun/](https://liuyib.github.io/hexo-theme-stun/)
+Detailed configuration, please visit: [https://liuyib.github.io/hexo-theme-stun/](https://liuyib.github.io/hexo-theme-stun/)
 
-## 浏览器支持
+## Browser Support
 
 IE >= 10
 
-## 开源协议
+## License
 
 [MIT](https://github.com/liuyib/hexo-theme-stun/blob/master/LICENSE)

README_zh_CN.md

+<p align="center"><a href="https://liuyib.github.io/hexo-theme-stun/" target="_blank" rel="noopener noreferrer"><img width="100" src="https://raw.githubusercontent.com/liuyib/picBed/master/hexo-blog/20190603093757.png" alt="stun logo"></a></p>
+
+<h3 align="center">一个漂亮、简洁的 hexo 主题</h3>
+
+<p align="center">
+  <a href="http://commitizen.github.io/cz-cli/" target="_blank" rel="noopener noreferrer">
+    <img alt="Commitizen friendly" src="https://img.shields.io/badge/commitizen-friendly-brightgreen.svg?style=flat-square">
+  </a>
+  <a href="https://github.com/liuyib/hexo-theme-stun/blob/master/LICENSE" target="_blank" rel="noopener noreferrer">
+    <img alt="GitHub" src="https://img.shields.io/github/license/liuyib/hexo-theme-stun.svg?style=flat-square">
+  </a>
+  <a href="https://hexo.io/zh-cn/" target="_blank" rel="noopener noreferrer">
+    <img alt="hexo" src="https://img.shields.io/badge/hexo-%3E%3D3.0-blue.svg?style=flat-square">
+  </a>
+  <a href="https://github.com/liuyib/hexo-theme-stun/releases" target="_blank" rel="noopener noreferrer">
+    <img alt="GitHub release" src="https://img.shields.io/github/release-pre/liuyib/hexo-theme-stun.svg?style=flat-square">
+  </a>
+</p>
+
+[English](https://github.com/liuyib/hexo-theme-stun/blob/master/README.md) | [中文简体](https://github.com/liuyib/hexo-theme-stun/blob/master/README_zh_CN.md)
+
+## 演示
+
+- [liuyib`s Blog](https://liuyib.github.io/)
+
+如果你正在使用 stun 主题，并希望像上面一样，在这里展示出来，你可以通过 [PR](https://github.com/liuyib/hexo-theme-stun/pulls) 将你的网站链接填写在这里。
+
+## 安装
+
+- 安装 stun
+
+进入 hexo 根目录，执行指令。
+
+``` bash
+git clone https://github.com/liuyib/hexo-theme-stun.git themes/stun
+```
+
+- 安装 pug 和 stylus（可选）
+
+如果你没有安装对 pug、stylus 的支持，还需执行指令。
+
+``` bash
+npm install --save-dev hexo-render-pug hexo-renderer-stylus
+```
+
+## 使用
+
+修改 hexo 根目录下的 `_config.yml` 文件。
+
+``` yml
+theme: stun
+```
+
+## 更新
+
+``` bash
+cd themes/stun
+
+git pull
+```
+
+## 配置
+
+如果你不想麻烦，你只需要填写网站 favicon 和你的头像的图片路径即可完成最基本的配置。其他的配置项都是默认的。
+
+``` yml
+favicon: # url or path
+
+avatar: # url or path
+```
+
+详细配置，请访问：[https://liuyib.github.io/hexo-theme-stun/](https://liuyib.github.io/hexo-theme-stun/)
+
+## 浏览器支持
+
+IE >= 10
+
+## 开源协议
+
+[MIT](https://github.com/liuyib/hexo-theme-stun/blob/master/LICENSE)

source/css/_common/back-top.styl

 #back-top
   display: none
   position: fixed
-  bottom: 5vh
   right: 2rem
+  bottom: 5vh
 
 .back-top-inner
   transform: rotate(-45deg)