update advanced routing doc

Author: lime008

docs/advanced/DynamicRouting.md

@@ -28,7 +28,7 @@ var CourseRoute = {
     })
   },
 
-  getComponents(callback) {
+  getComponents(location, callback) {
     require.ensure([], function (require) {
       callback(null, require('./components/Course'))
     })
@@ -38,4 +38,4 @@ var CourseRoute = {
 
 Now go look at what hacks you have in place to do this. Just kidding, I don't want to make you sad right now.
 
-Run the [huge apps](https://github.com/rackt/react-router/tree/master/examples/huge-apps) example with your web inspector open and watch code get loaded in as you navigate around the demo.
+Run the [huge apps](https://github.com/rackt/react-router/tree/master/examples/huge-apps) example with your web inspector open and watch code get loaded in as you navigate around the demo.