Add myself (turion) to the maintainers list for several packages

Following nh2's advice, I want to be more involved in nixpkgs,
and I'll start to review changes to programs that are important to me,
and that didn't have a long list of maintainers yet.

pkgs/applications/kde/okular.nix

@@ -21,7 +21,7 @@ mkDerivation {
   meta = with lib; {
     homepage = "http://www.kde.org";
     license = with licenses; [ gpl2 lgpl21 fdl12 bsd3 ];
-    maintainers = with maintainers; [ ttuegel ];
+    maintainers = with maintainers; [ ttuegel turion ];
     platforms = lib.platforms.linux;
   };
 }