title: github: how to reference an issue in a commit from a different repository?
body: <p>I have two repositories:</p>
  
  <ul>
  <li>Repository A</li>
  <li>Repository B</li>
  </ul>
  
  <p>I also have a project:</p>
  
  <ul>
  <li>Project X</li>
  </ul>
  
  <p>This Project X has Repository A and Repository B as linked repositories.</p>
  
  <p>In Repository A I created several issues:</p>
  
  <ul>
  <li>Issue 1</li>
  <li>Issue 2</li>
  <li>Issue 3</li>
  </ul>
  
  <p>All these issues are appearing on the kanban board of Project X.
  When I now do a commit on Repository B: </p>
  
  <pre><code>closes #1
  </code></pre>
  
  <p>The commit wont get linked to the Issue 1 of Repository A.
  Can I configure the project in a way that I can create such references from commits from different Repositories? Or do I use this wrong?</p>