[Feature Request] Allow customizing the output format of smartlog

[mfulbright]

For each revision that smartlog displays, it prints some information. I.e. at the moment it prints:

• The short hash of the commit
• The time since the commit was last modified
• Any branches pointing at the commit
• The commit message

It would be cool if smartlog had an argument where you could specify a format string that would control what's printed for each revision. E.g. I don't think I really care about the time since the commit was modified. I would love, on the other hand, if I could display a link to a PR on github that's tied to a branch pointing at the revision (though maybe it's a stretch to expect this to be possible).

[arxanas]

It certainly makes sense as a feature for smartlog, but at some point, you might just prefer to use jj, which already implements this with its templating engine 🙂.