Create use case example and structure

Change-Id: Ia4eff37921ee6d38b86fc3c50176757ef9d56ff8
Signed-off-by: Rich Bennett <rb2745@att.com>
Issue-ID: DOC-223
diff --git a/docs/index.rst b/docs/index.rst
index 32d9b93..fbcb897 100644
--- a/docs/index.rst
+++ b/docs/index.rst
@@ -11,6 +11,7 @@
    release/index
    guides/onap-developer/index
    guides/onap-user/index
+   use-cases/index