r-cli-tutorial-style">ember-cli-tutorial-style</a> that instantly adds CSS to the tutorial.
The addon works by creating a file called <code>ember-tutorial.css</code> and putting that file in the super-rentals <code>vendor</code> directory.
As Ember CLI runs, it takes the <code>ember-tutorial</code> CSS file and puts it in <code>vendor.css</code> (which is referenced in <code>/app/index.html</code>).
We can make additional style tweaks to <code>/vendor/ember-tutorial.css</code>, and the changes will take eff