title: Storyboard file in Xcode now showing up as an empty folder
body: <p>I opened my Xcode project this morning and found that the .storyboard file in my project now shows up as a folder named MainStoryboard.storyboard instead of an actual storyboard file.
  It seems to be the same when I open it in finder and any Time Machine backups, which I find strange because I've had it opened in Xcode more recently than some of the backups.</p>
  <p>Is there any way to recover the file or is all hope lost?</p>
  <p>This is what I see in the Project Navigator:</p>
  <p><img src="https://i.stack.imgur.com/UJbb9.png" alt="storyboard folder" /></p>