Add a docs/ossm folder for ossm specific instructions (openshift-service-mesh#142)

Signed-off-by: Nick Fox <[email protected]>

Author: nrfox

docs/ossm/README.md

@@ -0,0 +1,9 @@
+[Return to Sail Operator documentation](../)
+
+# User Documentation
+
+This documentation is specific to the OpenShift Service Mesh product and may differ slightly from the [Sail Operator documentation](../README.md). For OpenShift Service Mesh 3, this documentation should be prioritized over the [Sail Operator documentation](../README.md). However, the official source of truth is the product documentation available at [docs.redhat.com](https://docs.redhat.com). If a particular topic is not covered here, you can refer to the [Sail Operator documentation](../README.md) or [Istio.io](https://istio.io) documentation as supplementary resources.
+
+# Table of Contents
+
+TODO