title: Git - nested repositories
body: <p>I have a main project that has a component that comes from a separate remote repo that must also be updated/pushed in concert with the main project.  Not necessarily simultaneously (I'm <em>not</em> looking to have a push of the main project trigger a push of the component), but I should be able to push changes made to both the main project and component whenever I need to.</p>
  
  <p>How can I make it so, with a structure abstractly like:</p>
  
  <pre><code>/root working directory of main project
      /some dir
          |
          |-&gt; some file
          |
          |-&gt; some file
      /component
          |
          |-&gt; some file
          |
          |-&gt; some file
          /subdir of component
  </code></pre>
  
  <p>Component will be tracked separately from the rest?</p>