doc: remove style instruction that is not followed

Remove style guide instruction to place punctuation inside parentehses
and quotation marks. Those are not universally correct and we do not
follow those rules in cases where they are not correct.

PR-URL: https://github.com/nodejs/node/pull/23346


Reviewed-By: Trivikram Kamat <trivikr.dev@gmail.com>
Reviewed-By: Sakthipriyan Vairamani <thechargingvolcano@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Сковорода Никита Андреевич <chalkerx@gmail.com>