Merge pull request #1412 from quinton-hoole/2017-11-16-arch-roadmap

Automatic merge from submit-queue.

Add Architecture Roadmap

Moving from Google Doc: https://docs.google.com/document/d/1VEzP20JvIKckPrGSs_R-D4vlwFzMAaqJd-9Lvfyi3jw/edit#

First commit is a straight automated conversion of the original Google Doc (minus the embedded image).  I plan to add a few more tidy-up commits before this will be ready for final review.

cc original authors @bgrant0607 @thockin @smarterclayton

architecture/architecture.md

@@ -1,5 +1,8 @@
 # Kubernetes Design and Architecture
 
+A much more detailed and updated [Architectural
+Roadmap](contributors/devel/architectural-roadmap.md) is also available.
+
 ## Overview
 
 Kubernetes is a production-grade, open-source infrastructure for the deployment, scaling,