Integrate block storage docs, despite the fact they're WIP

docs/topics/block_storage.rst

@@ -13,6 +13,7 @@ Operations, such as creating a new volume and listing the eixsting ones, are
 perfomed via the :class:`.VolumeService`.
 
 .. code-block:: python
+
     vol = provider.block_store.volumes.create('Cloudbridge-vol', 1, 'us-east-1a')
     vol.wait_till_ready()
     provider.block_store.volumes.list()

docs/topics/overview.rst

@@ -8,3 +8,4 @@ Introductions to all the key parts of Cloudbridge you'll need to know:
     How to install Cloudbridge <install.rst>
     Connection and authentication setup <setup.rst>
     Launching instances <launch.rst>
+    Using block storage <block_storage.rst>