Add "Quick Cluster Install" (steps with Vagrant)

The current [Initializing the Cluster|http://example.com] page has good detail with screenshots, but it starts after (and assuming) the user already has multiple Nodes setup–but might want to know how to do it quickly with Virtual Machines for testing.

Let's rename [Do a Quick Install|http://example.com] to "Quick Couchbase Install" and add a new page under it in the menu called "Quick Cluster Install" with the attached steps and a link to the current [Initializing the Cluster|http://example.com] page for details/screenshots.

The attached photos list step-by-step how to initialize and start a cluster with Vagrant VMs, and would look best as a 2-column table with normal text in the left column and <codeph> text in the right column.