Adjust some contents in write_docs_en.rst for Contribue Documentation (#9147)

* Add some contents

* Adjust the content of the English version

* Fix some error, replace word generate with build

* Replace document with documentation

* Adjust contents

* Make links more visible

doc/v2/dev/write_docs_cn.rst

@@ -2,13 +2,14 @@
 如何贡献文档
 #############
 
-PaddlePaddle的文档包括中英文两个部分。文档都是通过 ``cmake`` 驱动 ``sphinx`` 编译生成，也可以利用paddlepaddle.org工具来编译和预览文档。
+PaddlePaddle的文档包括中英文两个部分。文档都是通过 ``cmake`` 驱动 ``sphinx`` 编译生成的，PaddlePaddle.org工具可以帮助我们实现这一编译过程，并提供更好的预览效果。
 
 如何构建文档
 ============
 
 PaddlePaddle的文档构建有两种方式，分别为使用paddlepaddle.org工具和不使用paddlepaddle.org工具，两种方式都有各自的优点，前者方便预览，后者方便开发者进行调试。这两种方式中又分别有使用docker和不使用docker的两种构建方法。
 
+我们建议使用PaddlePaddle.org工具来构建文档。
 
 使用PaddlePaddle.org工具
 ------------------------
@@ -31,7 +32,7 @@ PaddlePaddle.org工具可以配合Docker使用，需要在系统里先安装好D
     docker run -it -p 8000:8000 -v `pwd`:/var/content paddlepaddle/paddlepaddle.org:latest
 
 注意: PaddlePaddle.org 会在 -v (volume) 指定的内容存储库运行命令
-之后再用网页连到http://localhost:8000就可以在网页上生成需要的文档
+之后再用网页连到 http://localhost:8000 就可以在网页上生成需要的文档
 编译后的文件将被存储在工作目录 <paddlepaddle working directory>/.ppo_workspace/content。
 
 如果不想使用Docker，你还可以通过运行Django框架直接激活工具的服务器。使用下面的命令来运行它。
@@ -56,7 +57,7 @@ PaddlePaddle.org工具可以配合Docker使用，需要在系统里先安装好D
     python manage.py runserver
 
 工具服务器将读取环境变量 CONTENT_DIR 搜索代码库。请指定的PaddlePaddle工作目录给环境变量 CONTENT_DIR。
-之后再用网页连到http://localhost:8000就可以在网页上生成需要的文档。
+之后再用网页连到 http://localhost:8000 就可以在网页上生成需要的文档。
 编译后的文件将被存储在工作目录 <paddlepaddle working directory>/.ppo_workspace/content。
 
 想了解更多PaddlePaddle.org工具的详细信息，可以 `点击这里 <https://github.com/PaddlePaddle/PaddlePaddle.org/blob/develop/README.cn.md>`_ 。
@@ -96,7 +97,7 @@ PaddlePaddle.org工具可以配合Docker使用，需要在系统里先安装好D
 
    python -m SimpleHTTPServer 8088
 
-在浏览器中输入http://localhost:8088就可以看到编译生成的中/英文的文档页面和英文的API页面,下图为生成的英文文档首页示例。注意，示例中由于使用了sphinx的原始主题，所以页面的风格与官网并不一致，但这并不影响开发者进行调试。
+在浏览器中输入 http://localhost:8088 就可以看到编译生成的中/英文的文档页面和英文的API页面,下图为生成的英文文档首页示例。注意，示例中由于使用了sphinx的原始主题，所以页面的风格与官网并不一致，但这并不影响开发者进行调试。
 
 ..  image:: src/doc_en.png
     :align: center

doc/v2/dev/write_docs_en.rst

@@ -2,21 +2,20 @@
 Contribute Documentation
 ########################
 
-PaddlePaddle supports English documentation ``doc`` and Chinese documentation ``doc_cn``.
-Both are compiled by `cmake`_ and `sphinx`_ , the compiled documentations will be stored under ``doc`` and ``doc_cn`` directories.
-When using the PaddlePaddle.org to compile documentations, the compiled documentations will be stored under a consolidated directory: .ppo_workspace/content
+PaddlePaddle's documentation includes both Chinese and English versions. The documentation is built using the ``cmake`` command to drive the ``sphinx`` compiler. The PaddlePaddle.org tool helps us to implement this compilation process and provides better preview results.
 
-How to Build Documentations
-============
+How to build Documentation
+===========================
 
-We recommend using PaddlePaddle.org tool to build documentation
+PaddlePaddle's documentation is built in two ways: using the PaddlePaddle.org tool and without using it. Both methods have their own advantages. The former facilitates previewing, while the latter facilitates debugging by the developer. We could choose to build the documentation with Docker or without it in each of the above ways.
 
+We recommend using PaddlePaddle.org tool to build documentation.
 
-Use PaddlePaddle.org tool
---------------
-This is the recommended method to build documentation. It can compile documentation and preview the documentation in a web browser.
+Using PaddlePaddle.org tool
+-----------------------------
+This is the recommended method to build documentation, because it can automatically compile the documentation and preview the documentation directly in a web page. Note that, although you can preview the documentation in other ways, its style may not be consistent with the official website. Compiling with the PaddlePaddle.org tool produces a preview that will be consistent with the official website documentation style.
 
-The tool uses Docker, please install it on your system. Please check Docker official website on how to install Docker. You may use the following commands to activate the tool
+The PaddlePaddle.org tool can be used with Docker and Docker needs to be installed first. Please refer to `Docker's official website <https://docs.docker.com/>`_ on how to install Docker. After installing Docker, you may use the following commands to activate the tool
 
 ..  code-block:: bash
 
@@ -32,8 +31,8 @@ The tool uses Docker, please install it on your system. Please check Docker offi
     # Please specify the working directory through -v
     docker run -it -p 8000:8000 -v `pwd`:/var/content paddlepaddle/paddlepaddle.org:latest
 
-Note: PaddlePaddle.org will read the content repos specified in the -v (volume) flag of the docker run command
-Use a web browser and navigate to http://localhost:8000, click the buttons to compile the documentation
+Note: PaddlePaddle.org will read the content repos specified in the -v (volume) flag of the docker run commands
+Use a web browser and navigate to http://localhost:8000. Click the buttons to compile the documentation.
 The compiled documentations will be stored in <paddlepaddle working directory>/.ppo_workspace/content
 
 
@@ -58,19 +57,62 @@ If you don't wish to use Docker, you can also activate the tool through Django.
     pip install -r requirements.txt
     python manage.py runserver
 
-Use a web browser and navigate to http://localhost:8000, click the buttons to compile the documentation
+Specify the PaddlePaddle working directory for the environment variable CONTENT_DIR so that the tool could find where the working directory is.
+
+Use a web browser and navigate to http://localhost:8000. Click the buttons to compile the documentation
 The compiled documentations will be stored in <paddlepaddle working directory>/.ppo_workspace/content
 
-If you want to learn more on the PaddlePaddle.org, please `click here <https://github.com/PaddlePaddle/PaddlePaddle.org/blob/develop/README.md>`_ 。
+Please `click here <https://github.com/PaddlePaddle/PaddlePaddle.org/blob/develop/README.md>`_ for more information about the PaddlePaddle.org tool.
+
+
+Manually Building the Documentation
+-------------------------------------
+
+Build PaddlePaddle's documentation with Docker，you need to install Docker first. Please refer to `Docker's official website <https://docs.docker.com/>`_ on how to install Docker. After Docker is installed, you could use the scripts in the source directory to build the documentation.
+
+[TBD]
+
+If you do not wish to use Docker, you can also use the following commands to directly build the PaddlePaddle documentation.
+
+.. code-block:: bash
+
+   mkdir paddle
+   cd paddle
+   git clone https://github.com/PaddlePaddle/Paddle.git
+   mkdir -p build
+   cd build
+   cmake .. -DCMAKE_BUILD_TYPE=Release -DWITH_GPU=OFF -DWITH_MKL=OFF -DWITH_DOC=ON
+
+   # If you only need to build documents, use the following commands
+   make -j $processors gen_proto_py
+   make -j $processors paddle_docs paddle_docs_cn
+
+   # If you only need to build APIs, use the following commands
+   make -j $processors gen_proto_py framework_py_proto
+   make -j $processors copy_paddle_pybind
+   make -j $processors paddle_api_docs
+
+$processors indicates that as many processes as the CPU cores are started to compile in parallel. It should be set according to the number of CPU cores of your machine.
+
+After the compilation is complete, enter the ``doc/v2`` directory. If you chose to build documents, it will generate ``cn/html/`` and ``en/html`` subdirectories under this directory. If you chose to build APIs，it will generate``api/en/html`` subdirectory. Please enter these directories respectively and execute the following commands:
+
+.. code-block:: bash
+
+   python -m SimpleHTTPServer 8088
+
+Use a web browser and navigate to http://localhost:8000, you could see the compiled Chinese/English documents page and the English APIs page. The following figure is an example of the built English documents home page. Note that due to the sphinx's original theme used in the example, the style of the page is not consistent with the official website, but this does not affect the developer's debugging.
 
-How to write Documentations
-============
+..  image:: src/doc_en.png
+    :align: center
+    :scale: 60 %
 
-PaddlePaddle uses `sphinx`_ to compile documentations，Please check sphinx official website for more detail.
+How to write Documentation
+===========================
 
+PaddlePaddle uses `sphinx`_ to compile documentation，Please check sphinx official website for more detail.
 
 How to update www.paddlepaddle.org
-============================
+===================================
 
 Please create PRs and submit them to github, please check `Contribute Code <http://www.paddlepaddle.org/docs/develop/documentation/en/howto/dev/contribute_to_paddle_en.html>`_ 。
 PaddlePaddle develop branch will update the documentation once the PR is merged. User may check latest `Chinese Docs <http://www.paddlepaddle.org/docs/develop/documentation/zh/getstarted/index_cn.html>`_ and