maintainers: add polyfloyd

maintainers/maintainer-list.nix

···
     githubId = 1829032;
     name = "Paul Hendry";
   };
+  polyfloyd = {
+    email = "[e-mail]";
+    github = "polyfloyd";
+    githubId = 4839878;
+    name = "polyfloyd";
+  };
   polygon = {
     email = "[e-mail]";
     name = "Polygon";