title: Checkout branch in git submodule
body: <p>How do I change branches from within a submodule? When I run <code>git branch</code> from within the submodule, I see the following output:</p>
  
  <pre><code>&gt; git branch
    * (HEAD detached from 229a7b2)
    master
  </code></pre>
  
  <p>How would I put myself on a new branch? Like <code>development</code>?</p>