options: add display refresh rate

Signed-off-by: Myned <dev@bjork.tech>

machines/mynix/default.nix

@@ -8,6 +8,7 @@
     hostname = "mynix";
     width = 3440;
     height = 1440;
+    refresh = 100;
   };
 
   boot = {

options/custom/default.nix

@@ -22,6 +22,7 @@ in {
     ### Hardware
     width = mkOption {default = 1920;};
     height = mkOption {default = 1080;};
+    refresh = mkOption {default = 60;};
     ultrawide = mkOption {default = cfg.width * 9 / 16 > cfg.height;}; # Wider than 16:9
     hidpi = mkOption {default = cfg.scale > 1;};
     scale = mkOption {default = 1;};