Use proper toctree vs. direct links on the topics overview page

docs/topics/overview.rst

@@ -2,7 +2,8 @@ Using Cloudbridge
 =================
 Introductions to all the key parts of Cloudbridge you'll need to know:
 
-- `How to install Cloudbridge <install.html>`_
-- `Connection and authentication setup <setup.html>`_
-
+.. toctree::
+   :maxdepth: 1
 
+    How to install Cloudbridge <install.rst>
+    Connection and authentication setup <setup.rst>