meta: add note about email sync to CONTRIBUTING.md

PR-URL: #16340
Reviewed-By: Anatoli Papirovski <[email protected]>
Reviewed-By: James M Snell <[email protected]>
Reviewed-By: Jeremiah Senkpiel <[email protected]>
Reviewed-By: Michaël Zasso <[email protected]>
Reviewed-By: Colin Ihrig <[email protected]>
Reviewed-By: Tobias Nießen <[email protected]>
Reviewed-By: Yuta Hiroto <[email protected]>
Reviewed-By: Gireesh Punathil <[email protected]>
Reviewed-By: Gibson Fahnestock <[email protected]>

Refs: #16339 (comment)

Author: vsemozhetbyt

CONTRIBUTING.md

@@ -75,6 +75,10 @@ Create a branch and start hacking:
 ```text
 $ git checkout -b my-branch -t origin/master
 ```
+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.
 
 Any text you write should follow the [Style Guide](doc/STYLE_GUIDE.md),
 including comments and API documentation.