Add Manila to the list of images provided by Kolla

Add Manila and its developer website to the list of images
provided by Kolla in README.

DocImpact

Change-Id: Ibaa47c8825464566698d1ae068f5053834ed211a

README.rst

@@ -39,6 +39,7 @@ Kolla provides images to deploy the following OpenStack projects:
 - `Ironic <http://docs.openstack.org/developer/ironic/>`__
 - `Keystone <http://docs.openstack.org/developer/keystone/>`__
 - `Magnum <http://docs.openstack.org/developer/magnum/>`__
+- `Manila <http://docs.openstack.org/developer/manila`__
 - `Mistral <http://docs.openstack.org/developer/mistral/>`__
 - `Murano <http://docs.openstack.org/developer/murano/>`__
 - `Nova <http://docs.openstack.org/developer/nova/>`__