doc: add watson to collaborators

Closes: https://github.com/nodejs/node/issues/18943

PR-URL: https://github.com/nodejs/node/pull/19234
Reviewed-By: Gus Caplan <me@gus.host>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Richard Lau <riclau@uk.ibm.com>
Reviewed-By: Matteo Collina <matteo.collina@gmail.com>
Reviewed-By: Rich Trott <rtrott@gmail.com>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Jon Moss <me@jonathanmoss.me>
Reviewed-By: Roman Reiss <me@silverwind.io>
Reviewed-By: Ruben Bridgewater <ruben@bridgewater.de>

README.md

@@ -513,6 +513,8 @@ For more information about the governance of the Node.js project, see
 **Vse Mozhet Byt** <vsemozhetbyt@gmail.com> (he/him)
 * [watilde](https://github.com/watilde) -
 **Daijiro Wachi** <daijiro.wachi@gmail.com> (he/him)
+* [watson](https://github.com/watson) -
+**Thomas Watson** <w@tson.dk>
 * [whitlockjc](https://github.com/whitlockjc) -
 **Jeremy Whitlock** <jwhitlock@apache.org>
 * [XadillaX](https://github.com/XadillaX) -