Update README.md

Author: sokra

README.md

@@ -6,6 +6,8 @@
 
 ## Usage
 
+[Documentation: Using loaders](http://webpack.github.io/docs/using-loaders.html)
+
 ``` javascript
 var css = require("css!./file.css");
 // => returns css code from file.css, resolves imports and url(...)