Refer to https://github.com/PaddlePaddle/Paddle/issues/6305 (#6306)

This pull request adds "Build using Docker" documentation to the "Getting Started > Install and Build" menu on PaddlePaddle.org

doc/getstarted/build_and_install/index_cn.rst

@@ -13,7 +13,7 @@ PaddlePaddle提供pip和Docker的安装方式：
 
    pip_install_cn.rst
    docker_install_cn.rst
-
+   ../../howto/dev/build_cn.md
 
 编译流程
 ++++++++

doc/getstarted/build_and_install/index_en.rst

@@ -13,6 +13,7 @@ You can choose either pip or Docker to complete your install:
 
    pip_install_en.rst
    docker_install_en.rst
+   ../../howto/dev/build_en.md
 
 
 Build from Source

doc/howto/dev/build_cn.md

-# 编译PaddlePaddle和运行单元测试
+# 用Docker编译和测试PaddlePaddle
 
 ## 需要的软硬件
 

doc/howto/dev/build_en.md

-# Build PaddlePaddle from Source Code and Run Unit Test
+# Build using Docker
 
 ## What Developers Need