title: Pull request at GitHub results in Compare changes page - how to proceed?
body: <p>I wanted to fix some typos in a Microsoft documentation repo.  I clicked on its <strong><em>New pull request</em></strong> button.  That resulted in the following page being displayed:</p>
  
  <p><a href="https://i.stack.imgur.com/3mpf6.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/3mpf6.png" alt="enter image description here"></a></p>
  
  <p>As you can see, the green <strong><em>Create pull request</em></strong> button is disabled.  How do I proceed from here?  In other repos (such as for Amazon documentation), the process works differently, and I am able to directly create a pull request.</p>