Unhardcode stack-abandon and stack-adopt in conf

Related-prod: PROD-35308
Change-Id: I8ebed078eb39888aaf367074601dc87b739a32f0
diff --git a/README.rst b/README.rst
index 21bba9c..0b41d13 100644
--- a/README.rst
+++ b/README.rst
@@ -327,6 +327,17 @@
           # Add key without value to remove line from policy.json
           cloudformation:ListStacks:
 
+
+Enable stack abandon and/or stack adopt features:
+-------------------------------------------------
+
+.. code-block:: yaml
+
+    heat:
+      server:
+        enable_stack_abandon: true
+        enable_stack_adopt: true
+
 Upgrades
 ========