improve the progress bar documentation

Author: mansona

docs/components/progress-bar.md

@@ -1,9 +1,13 @@
 # Progress bar
 
+The progress bar component is designed to give some visual feedback to the user when they are navigating between routes. Internally it uses a service to keep track of route changes so you don't need to do anything special to make it work
+
 ## Usage
 
-Use the progress bar to indicate how far along on a page the user has viewed.
+Just make sure that you add the following code to the Application template and the component will take care of the rest!
 
 ```handlebars
 <EsProgressBar />
 ```
+
+The above demo doesn't look like much, but if you want to see it in action you need to navigate to a different route and keep an eye on the top of the screen. Try it now by clicking something in the table of contents and then navigate back to this page