doc: add BethGriggs to collaborators

PR-URL: #19610
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: Gibson Fahnestock <gibfahn@gmail.com>
Reviewed-By: Gireesh Punathil <gpunathi@in.ibm.com>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Yuta Hiroto <hello@hiroppy.me>
Reviewed-By: Ruben Bridgewater <ruben@bridgewater.de>
Reviewed-By: Richard Lau <riclau@uk.ibm.com>
Reviewed-By: Vse Mozhet Byt <vsemozhetbyt@gmail.com>
Reviewed-By: Joyee Cheung <joyeec9h3@gmail.com>

Author: BethGriggs

README.md

@@ -309,6 +309,8 @@ For more information about the governance of the Node.js project, see
 **Bryan English** <bryan@bryanenglish.com> (he/him)
 * [benjamingr](https://github.com/benjamingr) -
 **Benjamin Gruenbaum** <benjamingr@gmail.com>
+* [BethGriggs](https://github.com/BethGriggs) -
+**Beth Griggs** <Bethany.Griggs@uk.ibm.com> (she/her)
 * [bmeck](https://github.com/bmeck) -
 **Bradley Farias** <bradley.meck@gmail.com>
 * [bmeurer](https://github.com/bmeurer) -