Remove extra build environment documents

Author: tapaswenipathak

docs/builds.rst

@@ -172,106 +172,6 @@ If you're having trouble getting your version to build, try wiping out the exist
 Build environment
 -----------------
 
-Build environments use `Docker`_ to handle container virtualization. To perform
-any development on the Docker build system, you will need to set up `Docker`_ on
-your host system. Setup of Docker will vary by system, and so is out of the
-scope of this documentation.
-
-Once you have Docker set up, you will need to pull down our build image. These
-images are found on our `Docker Hub repository`_, the source comes from our
-`container image repo`_.
-
-.. note:: The size of the Docker images is around 5 to 9 GB.
-
-To get started using Docker for build environments, you'll need to pull down at
-least one build image. For example, to pull down our latest image::
-
-    docker pull readthedocs/build:latest
-
-The default image used by our build servers is :djangosetting:`DOCKER_IMAGE`.
-This would be a good place to start testing as the ``latest`` version could
-operate differently. See ``DOCKER_IMAGE`` below for setting this configuration
-option.
-
-After this image is downloaded, you can update your settings to use the new
-image -- see `Configuration`_.
-
-.. _`Docker`: http://docker.com
-.. _`Docker Hub repository`: https://hub.docker.com/r/readthedocs/build/
-.. _`container image repo`: https://github.com/readthedocs/readthedocs-docker-images
-
-Configuration
--------------
-
-There are several settings used to configure usage of virtual machines:
-
-DOCKER_ENABLE
-    True/False value used to enable the Docker build environment.
-
-    Default: :djangosetting:`DOCKER_ENABLE`
-
-DOCKER_LIMITS
-    A dictionary of limits to virtual machines. These limits include:
-
-        time
-            An integer representing the total allowed time limit (in
-            seconds) of build processes. This time limit affects the parent
-            process to the virtual machine and will force a virtual machine
-            to die if a build is still running after the allotted time
-            expires.
-
-        memory
-            The maximum memory allocated to the virtual machine. If this
-            limit is hit, build processes will be automatically killed.
-            Examples: '200m' for 200MB of total memory, or '2g' for 2GB of
-            total memory.
-
-    Default: :djangosetting:`DOCKER_LIMITS`
-
-DOCKER_IMAGE
-    Tag of a Docker image to use as a base image.
-
-    Default: :djangosetting:`DOCKER_IMAGE`
-
-DOCKER_SOCKET
-    URI of the socket to connect to the Docker daemon. Examples include:
-    ``unix:///var/run/docker.sock`` and ``tcp://127.0.0.1:2375``.
-
-    Default: :djangosetting:`DOCKER_SOCKET`
-
-DOCKER_VERSION
-    Version of the API to use for the Docker API client.
-
-    Default: :djangosetting:`DOCKER_VERSION`
-
-
-Local development
------------------
-
-On Linux development environments, it's likely that your UID and GID do not
-match the ``docs`` user that is set up as the default user for builds. In this
-case, it's necessary to make a new image that overrides the UID and GID for the
-normal container user::
-
-    contrib/docker_build.sh latest
-
-This will create a new image, ``readthedocs/build-dev:latest``. To build a
-different image, you can instead specify a version to build::
-
-    contrib/docker_build.sh 5.0
-
-This will create a new image, ``readthedocs/build-dev:5.0``.
-
-You can set a ``local_settings.py`` option to automatically patch the image
-names to the development image names that are built here:
-
-DOCKER_USE_DEV_IMAGES
-    If set to ``True``, replace the normal Docker image name used in building
-    ``readthedocs/build`` with the image name output for these commands,
-    ``readthedocs/build-dev``.
-
-The *Sphinx* and *Mkdocs* builders set the following RTD-specific environment variables when building your documentation:
-
 .. csv-table::
    :header-rows: 1