Update heat policy management

Related: PROD-34318

Change-Id: I7415238dbbd46b8d6a6639a86a2dafed99e623b7
diff --git a/README.rst b/README.rst
index 19a6229..21bba9c 100644
--- a/README.rst
+++ b/README.rst
@@ -313,7 +313,19 @@
           pool_max_overflow: 30
           pool_recycle: 600
 
-.. code-block::
+
+Change default service policy configuration:
+--------------------------------------------
+
+.. code-block:: yaml
+
+    heat:
+      server:
+        policy:
+          deny_stack_user: not role:heat_stack_user
+          deny_everybody: '!'
+          # Add key without value to remove line from policy.json
+          cloudformation:ListStacks:
 
 Upgrades
 ========