Reorganize block store docs

This change organizes the block store docs by topic rather than letting
autodoc organize methods by the order they appear in the _proxy.py file.

Change-Id: I743562a8c9a1dc7aaceef1d14c571c7a07855802

doc/source/users/proxies/block_store.rst

@@ -12,5 +12,32 @@ The block_store high-level interface is available through the ``block_store``
 member of a :class:`~openstack.connection.Connection` object.
 The ``block_store`` member will only be added if the service is detected.
 
+Volume Operations
+^^^^^^^^^^^^^^^^^
+
 .. autoclass:: openstack.block_store.v2._proxy.Proxy
-   :members:
+
+   .. automethod:: openstack.block_store.v2._proxy.Proxy.create_volume
+   .. automethod:: openstack.block_store.v2._proxy.Proxy.delete_volume
+   .. automethod:: openstack.block_store.v2._proxy.Proxy.get_volume
+   .. automethod:: openstack.block_store.v2._proxy.Proxy.volumes
+
+Type Operations
+^^^^^^^^^^^^^^^
+
+.. autoclass:: openstack.block_store.v2._proxy.Proxy
+
+   .. automethod:: openstack.block_store.v2._proxy.Proxy.create_type
+   .. automethod:: openstack.block_store.v2._proxy.Proxy.delete_type
+   .. automethod:: openstack.block_store.v2._proxy.Proxy.get_type
+   .. automethod:: openstack.block_store.v2._proxy.Proxy.types
+
+Snapshot Operations
+^^^^^^^^^^^^^^^^^^^
+
+.. autoclass:: openstack.block_store.v2._proxy.Proxy
+
+   .. automethod:: openstack.block_store.v2._proxy.Proxy.create_snapshot
+   .. automethod:: openstack.block_store.v2._proxy.Proxy.delete_snapshot
+   .. automethod:: openstack.block_store.v2._proxy.Proxy.get_snapshot
+   .. automethod:: openstack.block_store.v2._proxy.Proxy.snapshots