title: Generate .strings file later in Xcode
body: <p>I am currently localising a quite large Swift project and I have changed all strings in the .swift files to NSLocalizedString. Now it seems that I have to create a .strings file manually and add every string to this file for a base localisation.</p>
  
  <p>Is there a way to generate this file? As far as I can see there are about 4000 strings in the code and I cannot believe that this has to be done manually. I found the genstrings script in the Apple documentation but it seems that it was designed for objc only so it has no Swift support.  </p>