Enable RBAC for OpenContrail

PROD-17451

Change-Id: I55f1fc517369fa40d408f17748186f4a23d0909e
diff --git a/README.rst b/README.rst
index 215d855..bd4fc8f 100644
--- a/README.rst
+++ b/README.rst
@@ -1086,6 +1086,16 @@
               port: 9001
               protocol: http
 
+Enable RBAC for OpenContrail engine
+-----------------------------------
+.. code-block:: yaml
+
+    neutron:
+      server:
+        backend:
+          engine: contrail
+          rbac:
+            enabled: True
 
 Enhanced logging with logging.conf
 ----------------------------------