Docs: Clarify tsconfigRootDir in docs

[JoshuaKGoldberg]

Before You File a Documentation Request Please Confirm You Have Done The Following...

• I have looked for existing open or closed documentation requests that match my proposal.
• I have read the FAQ and my problem is not listed.

Suggested Changes

Pulling from https://twitter.com/_baxuz/status/1597248286108553216 & #6084 (comment): it's not explicitly mentioned in our docs when & why you would want to enable tsconfigRootDir.

...but that's about it. It'd be nice if we were more explicit that:

• It's for when your current working directory doesn't match up with your path relativity.
  • It's mentioned in the @typescript-eslint/parser README as:

  Relative paths are interpreted relative to the current working directory if tsconfigRootDir is not set. If you intend on running ESLint from directories other than the project root, you should consider using tsconfigRootDir.

• Having working directory mismatches is, to my understanding, an unfortunate and to-be-avoided situation?
  • We could add workarounds somewhere, such as Troubleshooting & FAQs?

Note: once #5984 is merged, we'll have the package READMEs and included API docs on the site.

Affected URL(s)

https://typescript-eslint.io/docs/linting/typed-linting/monorepos
https://typescript-eslint.io/docs/linting/troubleshooting

[JoshuaKGoldberg]

I'll say this is blocked on #6084 being merged. Once that's in, I can send more to the docs.

[JoshuaKGoldberg]

Meh, dup of #6208, and not really blocked.