docs(README): link to webpack 2 docs (#49)

README.md

@@ -21,7 +21,7 @@ This is useful for third-party modules that rely on global variables like `$` or
 npm install imports-loader
 ```
 
-<h2 align="center">Usage</h2>
+<h2 align="center"><a href="https://webpack.js.org/concepts/loaders">Usage</a></h2>
 
 Given you have this file `example.js`
 
@@ -75,8 +75,6 @@ module.exports = {
 };
 ```
 
-[Documentation: Using loaders](http://webpack.github.io/docs/using-loaders.html)
-
 <h2 align="center">Typical Use Cases</h2>
 
 ### jQuery plugins