eslint: ignore yarn directory and backup files

[stefanv]

While completing the exercises, yarn created a .yarn directory that created problems with the linter.

Emacs stores backup files as #<something>#, and these files also shouldn't be checked.

[github-actions[bot]]

Hello. Thanks for opening a PR on Exercism 🙂

We ask that all changes to Exercism are discussed on our Community Forum before being opened on GitHub. To enforce this, we automatically close all PRs that are submitted. That doesn't mean your PR is rejected but that we want the initial discussion about it to happen on our forum where a wide range of key contributors across the Exercism ecosystem can weigh in.

You can use this link to copy this into a new topic on the forum. If we decide the PR is appropriate, we'll reopen it and continue with it, so please don't delete your local branch.

If you're interested in learning more about this auto-responder, please read this blog post.

---

Note: If this PR has been pre-approved, please link back to this PR on the forum thread and a maintainer or staff member will reopen it.

[stefanv]

Any thoughts on this PR?

[SleeplessByte]

I don't wholly understand why https://github.com/exercism/eslint-config-typescript/blob/main/eslint.config.mjs#L10 is not capturing this (and why I don't have the issue locally).

I am not opposed to this PR if it fixes the issue for you (and everyone else), but I would like to understand why it's not picking up that ignore!

[SleeplessByte]

...and the answer is of course because we don't import that file :')

Eh. Yah. Okay.

'**/#*'
'.appends/**/*',
'.github/**/*',
'.vscode/**/*',
'.yarn/**/*',
'.pnp.*',
'node_modules/**/*',
'babel.config.cjs',
'jest.config.cjs',

This is probably the full list we need to ignore for generated / tooling?

If you agree, can you extend the list further adding the missing entries, and add an extra PR to the repo I linked above to add **/#* as well? If you link your GitHub to your Exercism account, you'll receive reputation for both.

Thanks for this @stefanv !

[SleeplessByte]

@stefanv would you still like to contribute this PR?