Add the pbr generated changelog to the docs

You have to run 'python setup.py sdist' to generate the authors
and changelog file, so I'm not sure how this will work out when
docs are pushed to the docs server.

Change-Id: I48c00712e3604c256e2c17a949409887beb8dbc1

doc/source/history.rst

@@ -0,0 +1 @@
+.. include:: ../../ChangeLog

doc/source/index.rst

@@ -22,5 +22,13 @@ For Contributors
 
    contributors/index
 
-For a listing of terms used throughout the SDK, including the names of
-projects and services supported by it, see the `Glossary <glossary.html>`_.
+General Information
+-------------------
+
+General information about the SDK including a glossary and release history.
+
+.. toctree::
+   :maxdepth: 1
+
+   Glossary of Terms <glossary>
+   Release History <history>