doc: add JacksonTian to collaborators

Added myself as a collaborator following the onboarding process.

PR-URL: #6388
Reviewed-By: Johan Bergström <bugs@bergstroem.nu>
Reviewed-By: Rich Trott <rtrott@gmail.com>
Reviewed-By: Evan Lucas <evanlucas@me.com>
Reviewed-By: Сковорода Никита Андреевич <chalkerx@gmail.com>

Author: JacksonTian

README.md

@@ -180,6 +180,7 @@ information about the governance of the Node.js project, see
 * [iarna](https://github.com/iarna) - **Rebecca Turner** <me@re-becca.org>
 * [isaacs](https://github.com/isaacs) - **Isaac Z. Schlueter** <i@izs.me>
 * [iWuzHere](https://github.com/iWuzHere) - **Imran Iqbal** <imran@imraniqbal.org>
+* [JacksonTian](https://github.com/JacksonTian) - **Jackson Tian** <shvyo1987@gmail.com>
 * [jbergstroem](https://github.com/jbergstroem) - **Johan Bergström** <bugs@bergstroem.nu>
 * [joaocgreis](https://github.com/joaocgreis) - **João Reis** <reis@janeasystems.com>
 * [julianduque](https://github.com/julianduque) - **Julian Duque** <julianduquej@gmail.com>