title: Confused by git submodules
body: <p>I have an app and have set it up to use git. In that app I have a folder that I have setup as a git module, something like this:</p>
  
  <pre><code>/app
    .git
    .gitmodules
    ...other-files
    /...other-folders
    /feature           # this is a sub-module
      .git
      ...other-files
      /...other-folders
  </code></pre>
  
  <p>Something seems wrong as when I make a changes in the <code>/feature</code> folder, then in the root folder do <code>git status</code>, it lists the changes in the sub-module.</p>
  
  <p>Also when I change the branch in the root folder, doing a <code>git status</code> in the sub-module lists lots of files.  Same if I change the branch in the sub-module, <code>git status</code> lists lots of changed files in the root folder.</p>
  
  <p>I thought of adding <code>/feature</code> to the root directory's <code>.gitignore</code>, but read that is the wrong approach?</p>
  
  <p>Is this expected? Maybe I am misunderstanding submodules?  The reason I added them is to give a contractor access to just a part of the codebase.</p>