Highlight change ids in rebase advice

[Veykril]

Fixes https://github.com/martinvonz/jj/issues/3561

Checklist

If applicable:

• [ ] I have updated CHANGELOG.md
  • I don't know if that needs mention as a new feature or not, let me know if it does
• [ ] I have updated the documentation (README.md, docs/, demos/)
• [ ] I have updated the config schema (cli/src/config-schema.json)
• [x] I have addedupdated tests to cover my changes

[martinvonz]

I don't know if that needs mention as a new feature or not, let me know if it does

Nah, I don't think so. I think in general, it makes sense to mention things that fit at least one of:

• Would break or surprise existing users' workflows
• Users would appreciate but would perhaps not notice if we don't mention it
• Are significant enough that users who don't yet use jj are encouraged to finally try it (or is enough to convince them to try it again)

There may be other good reasons, and that's just my opinion anyway.