Kubernetes 1.8 reference docs (#5632)

* Kubernetes 1.8 reference docs

* Kubectl reference docs for 1.8

* Update side bar with 1.8 kubectl and api ref docs links

docs/api-reference/v1.8/node_modules/optimist/example/short.js

@@ -0,0 +1,3 @@
+#!/usr/bin/env node
+var argv = require('optimist').argv;
+console.log('(%d,%d)', argv.x, argv.y);