doc: Make the docs index more hierarchical

With the standard RTD theme, the navigation sidebar flattens all TOCs listed
on the index page. Hack around this to make things look more organized.

doc/api/index.rst

@@ -0,0 +1,14 @@
+Classes and Functions
+=====================
+
+.. toctree::
+   :maxdepth: 2
+
+   api
+   request_and_response
+   status
+   errors
+   middleware
+   hooks
+   routing
+   util

doc/changes/index.rst

@@ -0,0 +1,6 @@
+Changelogs
+==========
+
+.. toctree::
+
+   0.2.0 <0.2.0>

doc/community/index.rst

@@ -0,0 +1,9 @@
+Community Guide
+===============
+
+.. toctree::
+   :maxdepth: 1
+
+   help
+   contribute
+   faq

doc/index.rst

@@ -80,48 +80,13 @@ Resources
 - `An Unladen Web Framework <http://blog.kgriffs.com/2013/07/02/python-fast-web-service-framework.html>`_
 - `The Definitive Introduction to Falcon <https://speakerdeck.com/cabrera/the-definitive-introduction-to-falcon>`_
 
-Community Guide
----------------
-
-.. toctree::
-   :maxdepth: 1
-
-   community/help
-   community/contribute
-   community/faq
-
-
-User Guide
-----------
+Documentation
+-------------
 
 .. toctree::
    :maxdepth: 2
 
-   user/intro
-   user/install
-   user/quickstart
-   user/tutorial
-
-
-Classes and Functions
----------------------
-
-.. toctree::
-   :maxdepth: 2
-
-   api/api
-   api/request_and_response
-   api/status
-   api/errors
-   api/middleware
-   api/hooks
-   api/routing
-   api/util
-
-Changelogs
-----------
-
-.. toctree::
-   :glob:
-
-   changes/*
+   community/index
+   user/index
+   api/index
+   changes/index

doc/user/index.rst

@@ -0,0 +1,10 @@
+User Guide
+==========
+
+.. toctree::
+   :maxdepth: 2
+
+   intro
+   install
+   quickstart
+   tutorial