Add myself to maintainers (#7881)

* Add myself to maintainers

* Add missing handle

Co-Authored-By: techknowlogick <matti@mdranta.net>

MAINTAINERS

@@ -31,3 +31,4 @@ Richard Mahn <rich.mahn@unfoldingword.org> (@richmahn)
 Mrsdizzie <info@mrsdizzie.com> (@mrsdizzie)
 silverwind <me@silverwind.io> (@silverwind)
 Gary Kim <gary@garykim.dev> (@gary-kim)
+Guillermo Prandi <gitea.maint@mailfilter.com.ar> (@guillep2k)