add self to maintainers

maintainers/maintainer-list.nix

···
       fingerprint = "48AD DE10 F27B AFB4 7BB0  CCAF 2D25 95A0 0D08 ACE0";
     }];
   };
+  ppenguin = {
+    name = "Jeroen Versteeg";
+    email = "[e-mail]";
+    github = "ppenguin";
+    githubId = 17690377;
+  };
   ppom = {
     name = "Paco Pompeani";
     email = "[e-mail]";