Bug/Feature Request: update vscode.git depedency so this works on vscode.dev

[alextorma]

This currently depends on vscode.git to highlight changes in a document.

It would be great if that were an opt-in feature, because as far as I can tell, that's the only thing preventing this from working in vscode.dev.

My dream implementation for this would be for isomorphic-git/lightningFS to handle git in the browser... I even tried to work it out myself, but I ran into issues getting my system set up to actually test the thing.

In any case, would it be possible to make the git features an option, so users could limp by on the web interface?

[piersdeseilligny]

Would need to test more, but I believe there's a few other bits of the architecture that are reliant on node, mainly surrounding the pdf generation. Not an impossible hurdle, but would need a bit of work which I unfortunately wouldn't have the time to work on for a few months. However if anyone wants to, please feel free to submit a PR!