title: How to bundle asset files from parent directory?
body: <p>We have a git repository in which a sub folder holds a flutter app:</p>
  <pre><code>project/.git
  project/app/*
  project/backend/*
  </code></pre>
  <p>Now I would like to bundle some files of the <code>.git</code> folder in the app:</p>
  <pre class="lang-yaml prettyprint-override"><code># pubspec.yaml
    assets:
      - ../.git/HEAD
      - ../.git/ORIG_HEAD
      - ../.git/refs/heads/
  </code></pre>
  <p>This works when running on an emulator:</p>
  <pre class="lang-dart prettyprint-override"><code>// somewhere in the app:
  final _head = await rootBundle.loadString('../.git/HEAD');
  </code></pre>
  <p>But when building the app in release mode, the files are not bundled what perfectly makes sense - but I wonder how we can copy/bundle the files.</p>
  <p>My naive approach would be to run a script that copies the files to the app folder, but that is brittle as we need to remember to run the script before each build. What would be a more consistent approach?</p>