maintainers: isabelroses add matrix

Author: isabelroses

maintainers/maintainer-list.nix

@@ -10414,6 +10414,7 @@
   };
   isabelroses = {
     email = "[email protected]";
+    matrix = "@isabel:isabelroses.com";
     github = "isabelroses";
     githubId = 71222764;
     name = "Isabel Roses";