title: How to create folder within project
body: <p>I want to have all my image files in a folder so that I can obtain all of them at the same time. I think the path should like this ...MyApp.app/image folder/1.png.
  But when I drag them into xcode with folder references created, there is no folder. The path is always MyApp.app/1.png.</p>
  
  <p>Also, I think I've dragged the files into the app several times. How to delete the files? It's not enough to just delete the references.</p>