docs: list supported and unsupported Git features

[martinvonz]

No description provided.

[arxanas]

Other topics you might want to mention, in some order:

• Merge commits (and maybe octopus merges?).
• Rebasing. (Maybe also commit deduplication as a part of rebasing? If a commit is merged into the main branch upstream, can you rebase on top on of it and skip the appropriate commit?)
• Orphan branches/unborn HEAD.
• Detached HEAD.
• Whether there's a reflog-like strucure. (Maybe the operation log is a superior replacement?)
• The staging area/partial commits. Obviously one of the features is that there's no more staging area, so you might want to explain how to achieve equivalent workflows for partial commits or moving changes across branches.
• Whether jj can be used with a bare Git repository backing it.
• Garbage collection/what kind of objects are cleaned up, if any.
• Object packing (both whether you can save disk space and whether jj will incur periodic repacking pauses, or perhaps whether jj generates a lot of object churn).

[spoerri]

Might want to mention cherry picking

[martinvonz]

Might want to mention cherry picking

For my understanding, what do you think I should say about it?

I ask because I think it's more relevant in https://github.com/martinvonz/jj/blob/main/docs/git-comparison.md (which I need to expand quite a bit). There I could explain how to achieve cherry-picking with jj. It could also make sense to mention in this doc how jj behaves after you do a git cherry-pick. So I think it could be documented in both places.

[spoerri]

more relevant in https://github.com/martinvonz/jj/blob/main/docs/git-comparison.md

OK, I guess this page could be more about which git repo features are supported.

how to achieve cherry-picking with jj

That'd be great, thank you

[martinvonz]

more relevant in https://github.com/martinvonz/jj/blob/main/docs/git-comparison.md

OK, I guess this page could be more about which git repo features are supported.

Exactly, that was my intent anyway. I'll try to fill in git-comparison.md soon. Perhaps it turns out to be too unclear what the difference between the two docs is and I'll have to merge them or restructure, but for now I'll continue writing them as two separate docs.

how to achieve cherry-picking with jj

That'd be great, thank you

I've added that to this PR.

[martinvonz]

I've updated git-comparison.md as well now. Please take a look if you have time.

[arxanas]

Looks good on my end. You might want to bold the subject for each bullet point to make it easier to skim through.

[martinvonz]

Looks good on my end.

Thanks for reviewing.

You might want to bold the subject for each bullet point to make it easier to skim through.

That seems like a good idea. I've updated both git-compatibility.md and git-comparison.md.