doc: clarify git config name/email requirements

The previous wording sounded like this was a necessary for
contributing. This clarifies that it is not, and tells people what
we do use their info for.

PR-URL: #22433
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Gus Caplan <me@gus.host>
Reviewed-By: Vse Mozhet Byt <vsemozhetbyt@gmail.com>
Reviewed-By: Refael Ackermann <refack@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Joyee Cheung <joyeec9h3@gmail.com>
Reviewed-By: Ruben Bridgewater <ruben@bridgewater.de>
Reviewed-By: Trivikram Kamat <trivikr.dev@gmail.com>
Reviewed-By: George Adams <george.adams@uk.ibm.com>

Author: addaleax

doc/guides/contributing/pull-requests.md

@@ -80,10 +80,15 @@ It is recommended to configure `git` so that it knows who you are:
 $ git config user.name "J. Random User"
 $ git config user.email "j.random.user@example.com"
 ```
-Please make sure this local email is also added to your
-[GitHub email list](https://github.com/settings/emails) so that your commits
-will be properly associated with your account and you will be promoted
-to Contributor once your first commit is landed.
+
+You can use any name/email address you prefer here. We only use the
+metadata generated by `git` using this configuration for properly attributing
+your changes to you in the `AUTHORS` file and the changelog.
+
+If you would like for the Github UI to link the commit to your account
+and award you the `Contributor` label after the changes have been merged,
+make sure this local email is also added to your
+[GitHub email list](https://github.com/settings/emails).
 
 ### Step 2: Branch