title: How do I add a Back Button to the Navigation Bar through Storyboard?
body: <p>I'm very perplexed right now. Everywhere online I am seeing tutorials to add a custom back button, but I can't even seem to get the default one going. </p>
  
  <p>In my MainViewController, I have <code>performSegueWithIdentifier(...)</code> and then on the other end, I want the Navigation Bar to have the back button on the left. How does one achieve this? I can't seem to find any tutorials online. I've tried having a UINavigationController, and whenever I drag the "Navigation Item" in the storyboard up to the Navigation Bar, my title gets replaced and there still isn't a back button. </p>
  
  <p>How do I add the default back button?</p>