Uplift internal linting

[AaronMoat]

Replacing #1346, but same motivation:

Currently, if .gitignore/other ignore files need to be fixed by format, you can get away with never having them fixed because lint never fails. I've seen cases where they're not pushed with autofix (unsure if always or just if no write perms?)
...
Fairly important to get right before pnpm / managing npmrc

Goal is:

• Lint is readonly, but autofixes still work in CI
• format and lint do the same things (but readonly vs write)
• Nice output

I'm still newish to this codebase, so there may be crimes here, and my manual and automated testing is somewhat limited, so things to look out for tests to add (or run) would be appreciated.

[changeset-bot]

🦋 Changeset detected

Latest commit: 6a10c00

The changes in this PR will be included in the next version bump.

This PR includes changesets to release 1 package

Name	Type
skuba	Minor

Not sure what this means? Click here to learn what changesets are.

Click here if you're a maintainer who wants to add another changeset to this PR

[72636c]

Description makes sense 👍. Just opining on the TODOs, I'll take a more detailed look later.

[72636c]

Bigly effort, ty 🙌

[72636c]

Thoughts on us having documentation (e.g. another page similar to https://seek-oss.github.io/skuba/CHANGELOG.html) that provides more context on each patch that we can link from the CLI?

Not for this PR, but I'm happy to take a look at this if we agree it's a decent idea. Not sure if it would be overkill for the average patch, though we tend to write detailed explanations already that end up buried in the changelog via Changesets.

[AaronMoat]

Yeah that could be good. Maybe if we give them IDs/names we could also later give a way to opt out of a change (e.g. node 20 later)

[72636c]

🚀

[AaronMoat]

Thanks, you're very good at copyediting :)