doc: add LiviaMedeiros to collaborators

Fixes: https://github.com/nodejs/node/issues/42828

PR-URL: https://github.com/nodejs/node/pull/43039
Reviewed-By: Antoine du Hamel <duhamelantoine1995@gmail.com>
Reviewed-By: Evan Lucas <evanlucas@me.com>
Reviewed-By: Rafael Gonzaga <rafael.nunu@hotmail.com>
Reviewed-By: Richard Lau <rlau@redhat.com>

.mailmap

@@ -300,6 +300,7 @@ Lakshmi Swetha Gopireddy <lakshmiswethagopireddy@gmail.com> <lgopired@in.ibm.com
 Lars-Magnus Skog <ralphtheninja@riseup.net> <lars.magnus.skog@gmail.com>
 Lasse R.H. Nielsen <lrn@chromium.org>
 Leeseean Chiu <leeseean@qq.com>
+LiviaMedeiros <livia@cirno.name> <74449973+LiviaMedeiros@users.noreply.github.com>
 Lucas Pardue <lucaspardue.24.7@gmail.com> <lucas.pardue@bbc.co.uk>
 Luke Bayes <lbayes@patternpark.com>
 Lydia Kats <llkats@gmail.com>

AUTHORS

@@ -3432,7 +3432,6 @@ Alexandru Comanescu <comanescu.robert93@gmail.com>
 madflow <madflow@web.de>
 Austin Kelleher <austinlkelleher@gmail.com>
 apeltop <sunshine@ptokos.com>
-Livia Medeiros <74449973+LiviaMedeiros@users.noreply.github.com>
 Nikolaos Papaspyrou <nikolaos@chromium.org>
 Matt Probert <1196252+mattpr@users.noreply.github.com>
 Roch Devost <roch.devost@gmail.com>

README.md

@@ -360,6 +360,8 @@ For information about the governance of the Node.js project, see
   **Shingo Inoue** <<leko.noor@gmail.com>> (he/him)
 * [linkgoron](https://github.com/linkgoron) -
   **Nitzan Uziely** <<linkgoron@gmail.com>>
+* [LiviaMedeiros](https://github.com/LiviaMedeiros) -
+  **LiviaMedeiros** <<livia@cirno.name>>
 * [lpinca](https://github.com/lpinca) -
   **Luigi Pinca** <<luigipinca@gmail.com>> (he/him)
 * [lundibundi](https://github.com/lundibundi) -