doc: add Gibson Fahnestock to TSC

Welcome Gibson to the TSC!

PR-URL: https://github.com/nodejs/node/pull/18481
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Michaël Zasso <targos@protonmail.com>
Reviewed-By: Ali Ijaz Sheikh <ofrobots@google.com>
Reviewed-By: Daniel Bevenius <daniel.bevenius@gmail.com>
Reviewed-By: Jon Moss <me@jonathanmoss.me>
Reviewed-By: Sakthipriyan Vairamani <thechargingvolcano@gmail.com>
Reviewed-By: Tiancheng "Timothy" Gu <timothygu99@gmail.com>
Reviewed-By: Evan Lucas <evanlucas@me.com>
Reviewed-By: Сковорода Никита Андреевич <chalkerx@gmail.com>
Reviewed-By: Richard Lau <riclau@uk.ibm.com>
Reviewed-By: Michael Dawson <michael_dawson@ca.ibm.com>

README.md

@@ -245,6 +245,8 @@ For more information about the governance of the Node.js project, see
 **Franziska Hinkelmann** <franziska.hinkelmann@gmail.com> (she/her)
 * [Fishrock123](https://github.com/Fishrock123) -
 **Jeremiah Senkpiel** <fishrock123@rocketmail.com>
+* [gibfahn](https://github.com/gibfahn) -
+**Gibson Fahnestock** <gibfahn@gmail.com> (he/him)
 * [indutny](https://github.com/indutny) -
 **Fedor Indutny** <fedor.indutny@gmail.com>
 * [jasnell](https://github.com/jasnell) -