Added Scope information for cluster management

Blueprint :
https://blueprints.launchpad.net/opencontrail/+spec/add-delete-nodes-roles

Change-Id: I15f94c9ccb085622a443ae6fb78a9e58c5e0f91c
Closes-Bug: #1788447

5.1/ansible-delete-roles-and-nodes.md

@@ -244,4 +244,9 @@ action it is expected to achieve (add/delete).
 
 New documentation has to be added for add and delete of roles.
 
-# 11. References
+# 11. Scope
+
+For release R5.1 only addition and deletion of Compute nodes via Ansible
+Deployer will be supported.
+
+# 12. References