adding a directory to git checkouk. By adding this, we can make sure the checkout is in goldens
repo. I wasn't able to access the files in the previous version.

Change-Id: Ibebe1e7d2f032dfe664d4591cca73a8b8a2413ad
Reviewed-on: https://flutter-review.googlesource.com/c/recipes/+/6780
Reviewed-by: Nurhan Turgut <nurhan@google.com>
Commit-Queue: Nurhan Turgut <nurhan@google.com>