Lint with Jarl

[VisruthSK]

Use Just Another R Linter for some code styling.

[VisruthSK]

@jgabry so for air we're going to add a GHA to format PRs right? Do you want to add jarl to that? This is what I'm doing in voucher, stanflow, etc.

[jgabry]

If it works well and we like it then yeah seems like a good idea