This template is using Onsen UI, a HTML5 framework that is focusing on the speed and ease of use. For details, please check out Onsen UI Website and its documents.
Here are the resources that might help you:
You need to edit index.html to have more tighter integration with AngularJS. More precisely, you need to add ng-app definition and call angular.module() to add onsen module to your app.
Here is the code snippet that you can copy & paste for quicker setup.
<!DOCTYPE HTML>
<html ng-app="myApp">
<head>
<meta charset="utf-8">
<meta name="viewport" content="width=device-width, initial-scale=1, maximum-scale=1, user-scalable=no">
<script src="components/loader.js"></script>
<link rel="stylesheet" href="components/loader.css">
<link rel="stylesheet" href="css/style.css">
<script>
angular.module('myApp', ['onsen']);
</script>
</head>
<body>
<ons-tabbar var="tabbar">
<ons-tabbar-item
icon="home"
label="Home"
page="navigator.html"
active="true"></ons-tabbar-item>
<ons-tabbar-item
icon="comment"
label="Comments"
page="page2.html"></ons-tabbar-item>
<ons-tabbar-item
icon="gear"
label="Settings"
page="page3.html"></ons-tabbar-item>
</ons-tabbar>
</body>
</html>