doc: add Daijiro Wachi to collaborators

PR-URL: nodejs/node#11676
Reviewed-By: Evan Lucas <evanlucas@me.com>

Author: watilde

README.md

@@ -337,6 +337,8 @@ more information about the governance of the Node.js project, see
 **Mike Tunnicliffe** <m.j.tunnicliffe@gmail.com>
 * [vkurchatkin](https://github.com/vkurchatkin) -
 **Vladimir Kurchatkin** <vladimir.kurchatkin@gmail.com>
+* [watilde](https://github.com/watilde) -
+**Daijiro Wachi** <daijiro.wachi@gmail.com> (he/him)
 * [whitlockjc](https://github.com/whitlockjc) -
 **Jeremy Whitlock** <jwhitlock@apache.org>
 * [yorkie](https://github.com/yorkie) -