Cut v0.2 branch + add v0.2.x tag (#820)

* Cut v0.2 branch + releases page

* Update doc-releases.md

Co-Authored-By: RichieEscarez <[email protected]>

* Update doc-releases.md

Co-Authored-By: RichieEscarez <[email protected]>

Author: RichieEscarez

doc-releases.md

@@ -0,0 +1,12 @@
+# Documentation Releases
+
+The following list shows the available versions of Knative documentation.
+Select the version that matches your installed version of Knative.
+
+## Released versions
+
+* [Branch: **`release-0.2`**](https://github.com/knative/docs/tree/release-0.2)
+
+## In development (pre-release) version
+
+* [Branch: **`master`**](https://github.com/knative/docs/tree/master)