add knockout to nav, update content

_data/nav.yml

@@ -223,6 +223,7 @@
   - url: "angularjs"
   - url: "bootstrap"
   - url: "jquery"
+  - url: "knockout"
   - url: "react"
   - url: "wordpress"
 

integrations/knockout.md

@@ -2,6 +2,10 @@
 layout: default
 title: KnockoutJS Integration
 title_nav: Knockout
+description: A custom binding that applies a TinyMCE Editor to the bound HTML element.
+keywords: integration integrate knockout knockoutjs
 ---
 
 Michael Papworth has developed a Knockout binding for TinyMCE. Check out his [tinymce-knockout-binding project](https://github.com/michaelpapworth/tinymce-knockout-binding) on Github.
+
+> This document is a work in progress. Click the contribute button (in the blue area above) to improve this page.