Be nice. Or else.
Since it's based on Git, I don't think it would work that way (I could be wrong). You would need to push (commit) your changes, I assume it would then show your update in the revision history (right panel).
The interesting use case would be, as you mentioned multiple people working on a single file and you both commit different changes to the same file. How would the app handle that?
There is no way to do it just from the Folio app, but if you're comfortable with the command line (or another Git client) you could do it.
We did some preliminary testing and it seems to work fine (you'll get everybody's commit messages in the app).
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