Add yardenshoham to maintainers (#21566)

[List of merged
PRs](https://github.com/go-gitea/gitea/pulls?q=is%3Apr+author%3Ayardenshoham+is%3Amerged)
(with many more on the way!)

Co-authored-by: Lauris BH <lauris@nix.lv>

MAINTAINERS

@@ -49,3 +49,4 @@ silentcode <silentcode@senga.org> (@silentcodeg)
 Wim <wim@42.be> (@42wim)
 xinyu <xinyu@nerv.org.cn> (@penlinux)
 Jason Song <i@wolfogre.com> (@wolfogre)
+Yarden Shoham <hrsi88@gmail.com> (@yardenshoham)