title: How do I move a group of controllers into a folder?
body: <p>I have generated a group of scaffolds with edited code inside, but now I want to move these groups of controllers into a folder, let's say its name is <code>admin</code>. How do I do it?</p>
  
  <p>I put <code>Admin::</code> in the controller already, moved them into a folder already, but still there is an error.</p>