doc: add yorkie to collaborators

PR-URL: #7004
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: Rich Trott <rtrott@gmail.com>

Author: Yazhong Liu

README.md

@@ -219,6 +219,7 @@ information about the governance of the Node.js project, see
 * [tunniclm](https://github.com/tunniclm) - **Mike Tunnicliffe** <m.j.tunnicliffe@gmail.com>
 * [vkurchatkin](https://github.com/vkurchatkin) - **Vladimir Kurchatkin** <vladimir.kurchatkin@gmail.com>
 * [whitlockjc](https://github.com/whitlockjc) - **Jeremy Whitlock** <jwhitlock@apache.org>
+* [yorkie](https://github.com/yorkie) - **Yorkie Liu** <yorkiefixer@gmail.com>
 * [yosuke-furukawa](https://github.com/yosuke-furukawa) - **Yosuke Furukawa** <yosuke.furukawa@gmail.com>
 * [zkat](https://github.com/zkat) - **Kat Marchán** <kzm@sykosomatic.org>