title: Navigation bar won't show after pushing a view controller
body: <p>I'm trying to move from a View Controller to another.
  I worte this function to use when the user tap on a button to move to the new view controller:</p>
  
  <pre><code>    @objc private func infoButtonTap(){
      let navVC = UINavigationController()
      navVC.addChild(AboutViewController())
      self.navigationController?.pushViewController(AboutViewController(), animated: true)
  }
  </code></pre>
  
  <p>The problem is that the new view controller is presented on the screen but I don't have a navigation bar and a back button to move back.
  I do not use Storyboard as I want to learn coding the UI.
  I tried few things I found here on Stackoverflow but none worked for me.
  How can I set the new view controller to have a navigation bar with back button?</p>