Initially I included just js/ionic.js and js/ionic-angular.js as per http://ionicframework.com/examples/nav/#/ which has
<link href="/vendor/font-awesome/css/font-awesome.css" rel="stylesheet">
<link rel="stylesheet" href="/ionic/css/ionic.css">
<script src="/ionic/js/ionic.js"></script>
<script src="/ionic/js/ionic-angular.js"></script>
For one, ionicframework.com/vendor/font-awesome/css/font-awesome.css doesn’t exist, but I wasn’t sure why in this case angular is included automatically, whereas in http://ionicframework.com/docs/guide/starting.html the HTML manually includes all of angular, including angular/{angular, angular-animate, angular-route} and so on.