maintainers: add farnoy

maintainers/maintainer-list.nix

···
     githubId = 1276854;
     name = "Florian Peter";
   };
+  farnoy = {
+    email = "[e-mail]";
+    github = "farnoy";
+    githubId = 345808;
+    name = "Jakub Okoński";
+  };
   fbeffa = {
     email = "[e-mail]";
     github = "fedeinthemix";