update readmes - source and site versions

README.md

@@ -0,0 +1,14 @@
+# Welcome to the source file repository for Knative documentation
+
+## View published docs
+
+Use the [Knative Documentation website](http://www.knative.dev/docs) to view the
+docs and learn about Knative.
+
+## Source files
+
+View the source files if you want to contribute a fix or add new content.
+Each release of the Knative docs are
+[branched](https://github.com/knative/docs/branches). If you are looking for an
+archived doc set, see the list of available versions in
+[Knative doc releases](./doc-releases.md).

docs/README.md

@@ -1,8 +1,9 @@
 
-Knative (pronounced kay-nay-tiv) extends Kubernetes to provide a set of
-middleware components that are essential to build modern, source-centric, and
-container-based applications that can run anywhere: on premises, in the cloud,
-or even in a third-party data center.
+Knative (pronounced kay-nay-tiv) extends
+[Kubernetes](https://kubernetes.io/docs/concepts/overview/what-is-kubernetes/)
+to provide a set of middleware components that are essential to build modern,
+source-centric, and container-based applications that can run anywhere: on
+premises, in the cloud, or even in a third-party data center.
 
 Each of the components under the Knative project attempt to identify common
 patterns and codify the best practices that are shared by successful,