Clarify that jQuery should be loaded first

jQuery needs to be loaded before *all* AngularJS modules in the app, 'cause otherwise AngularJS will not detect the presence of jQuery and animations (and I'm sure also other things) will not work as expected.

This requirement is implied in the tutorial, but not made absolutely clear to those who, like me, like to write their own code as the walk through the tutorial, and therefore might make the mistake of loading jQuery after Angular.