doc: move Timothy to TSC emeritus

PR-URL: https://github.com/nodejs/node/pull/24535


Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Richard Lau <riclau@uk.ibm.com>
Reviewed-By: Rich Trott <rtrott@gmail.com>
Reviewed-By: Gireesh Punathil <gpunathi@in.ibm.com>
Reviewed-By: Myles Borins <myles.borins@gmail.com>
Reviewed-By: Joyee Cheung <joyeec9h3@gmail.com>