title: How to add a page indicator inside the navigation bar?
body: <p>Like twitter did:</p>
  
  <p><img src="https://i.stack.imgur.com/CueGX.png" alt="enter image description here"></p>
  
  <p>I have a PageViewController inside a UITabBarController which in turn is inside a UINavigationController.</p>
  
  <p>Could anyone tell me how to show the page indicator inside the navigation bar?</p>