doc: add GeoffreyBooth to collaborators

PR-URL: https://github.com/nodejs/node/pull/31306


Reviewed-By: Myles Borins <myles.borins@gmail.com>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Bryan English <bryan@bryanenglish.com>
Reviewed-By: Richard Lau <riclau@uk.ibm.com>