docs: include README.rst in index.rst

These files were very similar so it makes sense to simply include one 
inside the other.

docs/index.rst

@@ -1,55 +1,11 @@
-python-semantic-release
-=======================
-
-Automatic semantic versioning for python projects. This is an python
-implementation of the
-`semantic-release <https://github.com/semantic-release/semantic-release>`__
-for js by Stephan Bönnemann. If you find this topic interesting you
-should check out his `talk from JSConf
-Budapest <https://www.youtube.com/watch?v=tc2UgG5L7WM>`__.
-
-Install
--------
-
-::
-
-    pip install python-semantic-release
-
-Usage
------
-
-The general idea is to have some sort of tag in commit messages that
-indicates certain types of changes. If a commit message lacks a tag it is
-ignored. Running release can be run locally or from a CI service.
-
-::
-
-  Usage: semantic-release [OPTIONS] COMMAND [ARGS]...
-
-  Options:
-  --major            Force major version.
-  --minor            Force minor version.
-  --patch            Force patch version.
-  --post             Post changelog.
-  --retry            Retry the same release, do not bump.
-  --noop             No-operations mode, finds the new version number without
-                     changing it.
-  -D, --define TEXT  setting="value", override a configuration value.
-  --help             Show this message and exit.
-
-  Commands:
-  changelog  Generate the changelog since the last release.
-  publish    Run the version task, then push to git and upload distributions.
-  version    Detect the new version according to git log and semver.
-
+.. include:: ../README.rst
 
 Documentation Contents
-======================
+----------------------
 
 .. toctree::
    :maxdepth: 1
 
-   Quickstart <../readme>
    Commands <commands>
    Parsing of commit logs <commit-log-parsing>
    Automatic releases <automatic-releases/index>