docs: add link to OSA deployment guide for adding a role

Provide a direct reference to the OpenStack-Ansible deploy guide, helping users understand how to integrate a new role into their deployment.

Change-Id: I774264ff5f2370793bb9b4cdb9200c1af40153e8

doc/source/index.rst

@@ -10,6 +10,42 @@ This role will install the following Upstart services:
     cloudkitty-api
     cloudkitty-processor
 
+Adding The Service to Your OpenStack-Ansible Deployment
+-------------------------------------------------------
+
+To add a new service to your OpenStack-Ansible (OSA) deployment:
+
+* Define ``rating_hosts`` in your ``conf.d`` or
+  ``openstack_user_config.yml``. For example:
+
+  .. code-block:: yaml
+
+      rating_hosts:
+        infra1:
+          ip: 172.20.236.111
+        infra2:
+          ip: 172.20.236.112
+        infra3:
+          ip: 172.20.236.113
+
+* Create respective LXC containers (skip this step for metal deployments):
+
+  .. code-block:: console
+
+     openstack-ansible openstack.osa.containers_lxc_create --limit cloudkitty_all,rating_hosts
+
+* Run service deployment playbook:
+
+  .. code-block:: console
+
+     openstack-ansible openstack.osa.cloudkitty
+
+For more information, please refer to the `OpenStack-Ansible project documentation <https://docs.openstack.org/project-deploy-guide/openstack-ansible/latest/>`_.
+
+Always verify that the integration is successful and that the service behaves
+correctly before using it in a production environment.
+
+
 Required Variables
 ==================