put Development Using Docker to the head and add a line of notification

doc/getstarted/build_and_install/docker_install_en.rst

@@ -9,6 +9,83 @@ Please be aware that you will need to change `Dockers settings
 of your hardware resource on Mac OS X and Windows.
 
 
+Development Using Docker
+------------------------
+
+Develpers can work on PaddlePaddle using Docker.  This allows
+developers to work on different platforms -- Linux, Mac OS X, and
+Windows -- in a consistent way.
+
+The general development workflow with Docker and Bazel is as follows:
+
+1. Get the source code of Paddle:
+
+   .. code-block:: bash
+
+      git clone --recursive https://github.com/paddlepaddle/paddle
+
+   
+   Here **git clone --recursive is required** as we have a submodule `warp-ctc <https://github.com/baidu-research/warp-ctc>`_.
+
+2. Build a development Docker image :code:`paddle:dev` from the source
+   code.  This image contains all the development tools and
+   dependencies of PaddlePaddle.
+
+
+   .. code-block:: bash
+
+      cd paddle
+      docker build -t paddle:dev -f paddle/scripts/docker/Dockerfile .
+
+
+3. Run the image as a container and mounting local source code
+   directory into the container.  This allows us to change the code on
+   the host and build it within the container.
+
+   .. code-block:: bash
+
+      docker run       \
+       -d              \
+       --name paddle   \
+       -p 2022:22      \
+       -v $PWD:/paddle \
+       -v $HOME/.cache/bazel:/root/.cache/bazel \
+       paddle:dev
+
+   where :code:`-d` makes the container running in background,
+   :code:`--name paddle` allows us to run a nginx container to serve
+   documents in this container, :code:`-p 2022:22` allows us to SSH
+   into this container, :code:`-v $PWD:/paddle` shares the source code
+   on the host with the container, :code:`-v
+   $HOME/.cache/bazel:/root/.cache/bazel` shares Bazel cache on the
+   host with the container.
+
+4. SSH into the container:
+
+   .. code-block:: bash
+
+      ssh root@localhost -p 2022
+
+5. We can edit the source code in the container or on this host.  Then
+   we can build using cmake
+
+   .. code-block:: bash
+
+      cd /paddle # where paddle source code has been mounted into the container
+      mkdir -p build
+      cd build
+      cmake -DWITH_TESTING=ON ..
+      make -j `nproc`
+      CTEST_OUTPUT_ON_FAILURE=1 ctest
+
+   or Bazel in the container:
+
+   .. code-block:: bash
+
+      cd /paddle
+      bazel test ...
+
+
 CPU-only and GPU Images
 -----------------------
 
@@ -104,78 +181,3 @@ container:
 
 Then we can direct our Web browser to the HTML version of source code
 at http://localhost:8088/paddle/
-
-
-Development Using Docker
-------------------------
-
-Develpers can work on PaddlePaddle using Docker.  This allows
-developers to work on different platforms -- Linux, Mac OS X, and
-Windows -- in a consistent way.
-
-The general development workflow with Docker and Bazel is as follows:
-
-1. Get the source code of Paddle:
-
-   .. code-block:: bash
-
-      git clone --recursive https://github.com/paddlepaddle/paddle
-
-
-2. Build a development Docker image :code:`paddle:dev` from the source
-   code.  This image contains all the development tools and
-   dependencies of PaddlePaddle.
-
-
-   .. code-block:: bash
-
-      cd paddle
-      docker build -t paddle:dev -f paddle/scripts/docker/Dockerfile .
-
-
-3. Run the image as a container and mounting local source code
-   directory into the container.  This allows us to change the code on
-   the host and build it within the container.
-
-   .. code-block:: bash
-
-      docker run       \
-       -d              \
-       --name paddle   \
-       -p 2022:22      \
-       -v $PWD:/paddle \
-       -v $HOME/.cache/bazel:/root/.cache/bazel \
-       paddle:dev
-
-   where :code:`-d` makes the container running in background,
-   :code:`--name paddle` allows us to run a nginx container to serve
-   documents in this container, :code:`-p 2022:22` allows us to SSH
-   into this container, :code:`-v $PWD:/paddle` shares the source code
-   on the host with the container, :code:`-v
-   $HOME/.cache/bazel:/root/.cache/bazel` shares Bazel cache on the
-   host with the container.
-
-4. SSH into the container:
-
-   .. code-block:: bash
-
-      ssh root@localhost -p 2022
-
-5. We can edit the source code in the container or on this host.  Then
-   we can build using cmake
-
-   .. code-block:: bash
-
-      cd /paddle # where paddle source code has been mounted into the container
-      mkdir -p build
-      cd build
-      cmake -DWITH_TESTING=ON ..
-      make -j `nproc`
-      CTEST_OUTPUT_ON_FAILURE=1 ctest
-
-   or Bazel in the container:
-
-   .. code-block:: bash
-
-      cd /paddle
-      bazel test ...