Adding details to README

Author: Elisabeth Hendrickson

README.md

@@ -5,9 +5,12 @@ title: Extending Cloud Foundry
 Extending Cloud Foundry
 ========
 
-This guide explains how to extend a Cloud Foundry instance with user-supplied services and custom buildpacks. 
-Other guides include:
+This guide explains how to extend a Cloud Foundry instance with user-supplied services.
 
-*  [Deploying Applications](https://github.com/cloudfoundry/docs-dev-guide): a guide for developers on deploying and troubleshooting applications running in Cloud Foundry. Note that this content is shared with the open source context and therefore will have the name Cloud Foundry throughout.
+This doc is one of several doc repositories that go into a complete documentation set.
 
-More coming soon.
+The contents here are structured as a topic repository intended to be
+compiled into a larger document with
+[Bookbinder](http://github.com/pivotal-cf/docs-bookbinder).
+
+For the master repository, see [docs-book-cloudfoundry](https://github.com/cloudfoundry/docs-book-cloudfoundry).