maintainers: add nomisiv

maintainers/maintainer-list.nix

···
     githubId = 148037;
     name = "Joachim Breitner";
   };
+  nomisiv = {
+    email = "[e-mail]";
+    github = "NomisIV";
+    githubId = 47303199;
+    name = "Simon Gutgesell";
+  };
   noneucat = {
     email = "[e-mail]";
     github = "noneucat";