title: How to add file to a previous commit?
body: <p>In last hour or so i have modified files </p>
  
  <pre><code>A
  ATest
  B
  BTest
  </code></pre>
  
  <p>In order to make sure my commit messages line up with the actual change, committed <code>A</code> with a description. Unfortunately i have not included <code>ATest</code> into that commit.</p>
  
  <p>Meanwhile, still not committed are <code>B</code> and <code>BTest</code>. </p>
  
  <p>What is the best way to proceed at this point? I'd like to either:</p>
  
  <ol>
  <li>Revert previous commit without affecting my currently uncommitted files?</li>
  <li>Add another file under the same description to the previous commit?</li>
  </ol>