doc: add addaleax to collaborators

PR-URL: #6224
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Evan Lucas <evanlucas@me.com>
Reviewed-By: Rich Trott <rtrott@gmail.com>
Reviewed-By: Ben Noordhuis <info@bnoordhuis.nl>
Reviewed-By: Myles Borins <myles.borins@gmail.com>

Author: addaleax

README.md

@@ -167,6 +167,7 @@ information about the governance of the Node.js project, see
 
 ### Collaborators
 
+* [addaleax](https://github.com/addaleax) - **Anna Henningsen** <anna@addaleax.net>
 * [AndreasMadsen](https://github.com/AndreasMadsen) - **Andreas Madsen** <amwebdk@gmail.com>
 * [benjamingr](https://github.com/benjamingr) - **Benjamin Gruenbaum** <benjamingr@gmail.com>
 * [brendanashworth](https://github.com/brendanashworth) - **Brendan Ashworth** <brendan.ashworth@me.com>