title: Create a Xcode 8 extension but no option on Xcode->editor
body: <p>macOS 10.12, Xcode 8.1</p>
  
  <p>I had created a Xcode extension like:
  <a href="https://medium.com/@victor_wang/build-your-own-xcode-8-source-editor-extension-5c728b1f3fa5#.si1m0h95k" rel="nofollow noreferrer">Build your own Xcode 8 Source Editor Extension</a> and run it, but on the develop Xcode no option with my extension.</p>
  
  <p><a href="https://i.stack.imgur.com/Pk39F.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/Pk39F.png" alt="enter image description here"></a></p>
  
  <p><code>System Preferences</code>-><code>Extensions</code> have my extension: <a href="https://i.stack.imgur.com/oNx1O.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/oNx1O.png" alt="enter image description here"></a></p>
  
  <p>What is going on？</p>