Provide structure for VNFs

Add to index hierarchy guides/onap-developer/architecture
Create section template vnf-reference

Change-Id: If1b7b2b89de906c66e43382a9bc9dc2bee4086e5
Issue-ID: DOC-260
Signed-off-by: Rich Bennett <rb2745@att.com>
diff --git a/docs/guides/onap-developer/architecture/references.rst b/docs/guides/onap-developer/architecture/references.rst
index b152795..7d8334d 100644
--- a/docs/guides/onap-developer/architecture/references.rst
+++ b/docs/guides/onap-developer/architecture/references.rst
@@ -110,6 +110,15 @@
    CCSDK SLI Northbound Interface <../../../submodules/ccsdk/sli/northbound.git/docs/architecture.rst>
    CCSDK SLI Plugins <../../../submodules/ccsdk/sli/plugins.git/docs/architecture.rst>
 
+VNFs
+----
+
+.. toctree::
+   :maxdepth: 1
+   :titlesonly:
+
+
+ 
 Other
 -----