Added stable interface and release information to documentation

Fixed README.rst formatting and added information about stable
interfaces for Patrole and release notes and versioning.

Change-Id: I2ba7c8b7dd2b4db82f19e661ef798f95e588ee62
diff --git a/README.rst b/README.rst
index c527c3b..ad8add0 100644
--- a/README.rst
+++ b/README.rst
@@ -24,11 +24,21 @@
 Currently, Patrole supports policies contained in code and in policy.json files.
 If both exist, the policy actions in the policy.json are prioritized.
 
+Stable Interface
+----------------
+Patrole offers a stable interface that is guaranteed to be backwards compatible and
+can be directly consumed by other projects. Currently, rbac_exceptions.py and
+rbac_policy_parser.py are guaranteed to be stable.
+
+Release Versioning
+------------------
+`Patrole Release Notes <https://docs.openstack.org/releasenotes/patrole/>`_ show
+what changes have been released.
+
 .. _test-flows:
 
 Test Flows
 ----------
-
 There are several possible test flows.
 
 If the ``rbac_test_role`` is allowed to access the endpoint:
@@ -47,7 +57,7 @@
 
     Certain services like Neutron *intentionally* raise a 404 instead of a 403
     for security concerns. Patrole accomodates this behavior by anticipating
-    a 404 instead of a 403, if specified through a special argument. For more
+    a 404 instead of a 403, using the ``expected_exception`` argument. For more
     information about Neutron's policy enforcement, see:
     `<https://docs.openstack.org/developer/neutron/devref/policy.html#request-authorization>`__.
 
@@ -70,7 +80,6 @@
 
 Test Execution Workflow
 -----------------------
-
 The workflow is as follows:
 
 #. Each test uses the ``rbac_rule_validation.action`` decorator, like below: ::