doc(README.md): add link to the workflow GH repo

Author: Aaron Schlesinger

README.md

@@ -4,6 +4,8 @@
 
 Deis (pronounced DAY-iss) is an open source PaaS that makes it easy to deploy and manage applications on your own servers. Deis builds on [Kubernetes](http://kubernetes.io/) to provide a lightweight, easy and secure way to deploy your code to production.
 
+For more information on the Deis workflow, please visit the main project page at https://github.com/deis/workflow.
+
 ## Beta Status
 
 This Deis component is currently in beta status, and we welcome your input! If you have feedback, please [submit an issue](https://github.com/deis/builder/issues). If you'd like to participate in development, please read the "Development" section below and [submit a pull request](https://github.com/deis/builder/pulls).