Added a maintainer

lib/maintainers.nix

···
   orbitz = "Malcolm Matalka <[e-mail]>";
   page = "Carles Pagès <[e-mail]>";
   paholg = "Paho Lurie-Gregg <[e-mail]>";
+  pakhfn = "Fedor Pakhomov <[e-mail]>";
   pashev = "Igor Pashev <[e-mail]>";
   phreedom = "Evgeny Egorochkin <[e-mail]>";
   pierron = "Nicolas B. Pierron <[e-mail]>";