Include docker/README.rst

So the docker documentation is available on docs.softwareheritage.org instead
of linking to the source on Phabricator

docs/getting-started.rst

@@ -12,7 +12,7 @@ steps detailed below.
 
 
 Using Docker
-++++++++++++
+------------
 
 The easiest way to run a Software Heritage instance is to use Docker and
 docker-compose. Please refer to the `docker-compose documentation
@@ -45,15 +45,13 @@ Code Now' feature of the archive web interface:
   http://localhost:5080/browse/origin/save/
 
 For details and an overview of what you can do with your Software Heritage,
-see `docker/README.md`_
+see the full :ref:`docker-environment` documentation.
 
 Enjoy filling your hard drives!
 
-.. _docker/README.md: https://forge.softwareheritage.org/source/swh-environment/browse/master/docker/
-
 
 Hacking the archive
-+++++++++++++++++++
+-------------------
 
 If you want to hack the code of the Software Heritage Archive, a bit more work
 will be required.

docs/getting-started-index.rst → docs/getting-started/index.rst

@@ -2,11 +2,12 @@ Getting started
 ===============
 
 .. this index file is used to force a hierarchy in the toctree,
-   even though these two files are in the same directory
+   even though these two files are in the parent directory
 
 .. toctree::
    :maxdepth: 2
    :titlesonly:
 
-   getting-started
-   developer-setup
+   ../getting-started
+   ../developer-setup
+   using-docker

docs/getting-started/using-docker.rst

+.. _docker-environment:
+
+.. include:: ../../../docker/README.rst

docs/index.rst

@@ -186,7 +186,7 @@ Indices and tables
    :titlesonly:
    :hidden:
 
-   getting-started-index
+   getting-started/index
    architecture/index
    contributing/index
    tutorials/index