title: Deploy an account-wide read-only SSH key onto GitHub
body: <p>I have an SSH server that I share with friends. We use it to connect to our GitHubs. Now I've generated an SSH keypair on it, and would like to add <code>id_rsa.pub</code> to my account, <strong>with R/O access to all my repositories</strong> (and future repos) (and my friends will repeat this). The problem is, I can't find a checkbox that reads "Make this key read-only", which is supposed to appear in the blue circle. Can I?</p>
  
  <p><a href="https://i.stack.imgur.com/3F8Tv.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/3F8Tv.png" alt="GitHub screenshot"></a>
  Oh, yes. With that key it should be able to read all my repositories, as well as new repos that are created after adding the key without changing more settings (i.e. Once-And-For-All).</p>
  
  <p>The requirement isn't that complicated. I just want a once-and-for-all solution, no matter how complex it is. </p>