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/divide.js

@@ -0,0 +1,8 @@
+#!/usr/bin/env node
+
+var argv = require('optimist')
+    .usage('Usage: $0 -x [num] -y [num]')
+    .demand(['x','y'])
+    .argv;
+
+console.log(argv.x / argv.y);