Docs: Mention how to ask for help with PRs

[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

From #6554 (comment):

(apologies if you're the wrong person to ping - couldn't find a doc on process for these kinds of questions in the contributing docs)

Indeed, we don't explicitly say how to ask for help or whether it's ok to ping folks directly.

Today, the right step is to just post a comment. You don't need to tag anybody - we'll see it regardless of the tag (the joy and pain of GitHub notifications 🥲). One of us will drop by and help when we can.

Affected URL(s)

https://typescript-eslint.io/contributing/pull-requests