Add link to "Who uses CSSOM.js"

Author: NV

README.mdown

@@ -32,3 +32,5 @@ To use it with Node.js:
     npm install cssom
 
 ## [Specs](http://nv.github.com/CSSOM/spec/)
+
+## [Who uses CSSOM.js](https://github.com/NV/CSSOM/wiki/Who-uses-CSSOM.js)