Add aodh and gnocchi to the plugin registry

The comment is their keystone service entry.

Change-Id: I896d5c594fa0c61924dbf4527215cc543b6e43e7
diff --git a/doc/source/plugin-registry.rst b/doc/source/plugin-registry.rst
index 99bfb85..428efc4 100644
--- a/doc/source/plugin-registry.rst
+++ b/doc/source/plugin-registry.rst
@@ -20,6 +20,10 @@
 +--------------------+-------------------------------------------+--------------------+
 |Plugin Name         |URL                                        |Comments            |
 +--------------------+-------------------------------------------+--------------------+
+|aodh                |git://git.openstack.org/openstack/aodh     | alarming           |
++--------------------+-------------------------------------------+--------------------+
+|gnocchi             |git://git.openstack.org/openstack/gnocchi  | metric             |
++--------------------+-------------------------------------------+--------------------+
 |magnum              |git://git.openstack.org/openstack/magnum   |                    |
 +--------------------+-------------------------------------------+--------------------+
 |sahara              |git://git.openstack.org/openstack/sahara   |                    |