title: Adding classes in Xcode
body: <p>I'm new to Xcode and have a set of instructions for a library that I need to import.
  The documentations says:</p>
  
  <blockquote>
    <p>Please add X.h and X.m into project by clicking Classes, Add and
    Existing Files.</p>
  </blockquote>
  
  <p>Q: Where is the "Classes" menu?</p>