Documentation: Update WA3 Documentation

Update the documentation and build system for producing documentation for
WA3 with support for automatic building on readthedocs.

Note: This is currently a WIP.

doc/source/plugins.rst

@@ -0,0 +1,61 @@
+.. _plugin-reference:
+
+=================
+Plugin Reference
+=================
+
+This section lists Plugins that currently come with WA3. Each package below
+represents a particular type of extension (e.g. a workload); each sub-package of
+that package is a particular instance of that extension (e.g. the Andebench
+workload). Clicking on a link will show what the individual extension does,
+what configuration parameters it takes, etc.
+
+For how to implement you own Plugins, please refer to the guides in the
+:ref:`writing plugins <writing-plugins>` section.
+
+.. raw:: html
+
+   <style>
+   td {
+      vertical-align: text-top;
+   }
+   </style>
+   <table <tr><td>
+
+.. toctree::
+   :maxdepth: 2
+
+   plugins/workloads
+
+.. raw:: html
+
+   </td><td>
+
+.. toctree::
+   :maxdepth: 2
+
+   plugins/instruments
+
+
+.. raw:: html
+
+   </td><td>
+
+.. toctree::
+   :maxdepth: 2
+
+   plugins/output_processors
+
+.. raw:: html
+
+   </td><td>
+
+.. toctree::
+   :maxdepth: 2
+
+   plugins/targets
+
+.. raw:: html
+
+   </td></tr></table>
+