examples/app/views/layouts/application.html.erb
<!DOCTYPE html>
<html>
<head>
<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.4/css/bootstrap.min.css">
</head>
<body>
<div class="page-header">
<h1>Tagfiles example</h1>
</div>
<div class="content">
<%= yield %>
</div>
</body>
</html>