title: Edit git commit message in a dedicated tab
body: <p>As an Atom user, I am used that when committing staged changes a new buffer is opened where I can edit the commit message. In particular, the advantages are:</p>
  
  <ul>
  <li>existing spell check is available</li>
  <li>I can provide a one line comment and an additional longer description</li>
  <li>I see a list of files to be committed (similar to the case when using the CLI)</li>
  </ul>
  
  <p>What is the vscode equivalent? So far I found two options:</p>
  
  <ol>
  <li><code>Command Palette -&gt; Git: commit (staged)</code></li>
  <li>Use the activity bar (where I see the staged files but still get a limited editing option of the commit message)</li>
  </ol>