maintainers: add ghostbuster91

maintainers/maintainer-list.nix

···
     githubId = 3217744;
     name = "Peter Ferenczy";
   };
+  ghostbuster91 = {
+    name = "Kasper Kondzielski";
+    email = "[e-mail]";
+    github = "ghostbuster91";
+    githubId = 5662622;
+  };
   ghuntley = {
     email = "[e-mail]";
     github = "ghuntley";