If you want to keep track of what is done and what is remaining eventually you will need to update that file.
This will quickly lead to version control conflicts.
Issue trackers I think are the way to go. You can integrate with one using their API.
Imagine 2 team members that are in agreement add leaf 2 nodes. That would trigger a version control conflict.
Now imagine that situation in a team of 5, or 10. It becomes hard to maintain.
If you want to keep track of what is done and what is remaining eventually you will need to update that file.
This will quickly lead to version control conflicts.
Issue trackers I think are the way to go. You can integrate with one using their API.