cli: add another tip to the "max snapshot size" error

[thoughtpolice]

A helpful additional tip, suggested by Fynn Schmitt-Ulms.

Closes #3912.

Checklist

If applicable:

• I have updated CHANGELOG.md
• I have updated the documentation (README.md, docs/, demos/)
• I have updated the config schema (cli/src/config-schema.json)
• I have added tests to cover my changes

[martinvonz]

I'm a little worried that people will follow this advice and expect everything to work after it, but it typically just makes the next command fail in the same way, right?

[ilyagr]

Perhaps the distinction should be made that with --config-toml, the file will likely get snapshotted and not warn anymore, while with --ignore-working-copy, it will not. Something like:

• Run jj --config-toml 'snapshot.max-new-file-size={}' st
  This will increase the maximum file size allowed for new files, for this command
  only. Any such command will snapshot all the files under the higher limit.
  They will no longer be considered "new", and this
  warning should not appear again until other large files are added to the repository.
• Run a one-off informational command with --ignore-working-copy (e.g. jj log --ignore-working-copy).
  This will ignore changes to the working copy. No files will be snapshotted and this warning will occur again on the next command.

[thoughtpolice]

I'm a little worried that people will follow this advice and expect everything to work after it, but it typically just makes the next command fail in the same way, right?

Yeah, I actually got into a few hurdles with this and tried my own advice here and it didn't really help anyway since the workspace became stale anyway too, requiring an update which required an ignored snapshot. So I think we'll close this and we need to address the original ticket another way, somehow. We can file another PR for this, in the mean time I think closing this one is fine.