title: why bootstrap navbar doesn't set 'active' class?
body: <p>When user clicks an item in navbar, bootstrap doesn't update the 'active' class to the clicked item.</p>
  
  <p>The question is why it's not implemented in bootstrap itself? </p>
  
  <p>I'm new to web dev in general, and new to bootstrap, and am curious what their itention is.</p>