A view is just html, $this is generally the controller (there is a view class which is portable - it's similar).
So - just write html ...
<html>
<body>
<h1>Hello World</h1>
</body>
</html>The constroller has a render function.
Using this the html is more of a fragment:
<div class="alert alert-success">
You can just write bootstrap fragments
</div>because - by default it is inserted in a .col element
<html>
<head>
<link type="text/css" rel="stylesheet" href="-[ bootstrap css ]-" />
</head>
<body>
<div class="container-fluid">
<div class="row">
<div class="col">
--- your view inserted here ---
</div>
</div>
</div>
<script type="text/javascript" src="-[ bootstrap js ]"></script>
</body>
</html>