Update keystone policy management

Related: PROD-34318

Change-Id: I0a4b1fc49457b2543e34b02e198dbbf3dd450c57
diff --git a/README.rst b/README.rst
index ab7a965..ee64e22 100644
--- a/README.rst
+++ b/README.rst
@@ -834,6 +834,20 @@
           ossyslog:
             enabled: true
 
+
+Change default service policy configuration:
+--------------------------------------------
+
+.. code-block:: yaml
+
+    keystone:
+      server:
+        policy:
+          admin_or_token_subject: 'rule:token_subject'
+          service_admin_or_token_subject": 'rule:service_or_admin'
+          # Add key without value to remove line from policy.json
+          identity:get_region:
+
 Usage
 =====