refactor: make the whole thing more generic

modules/nixos/hardware/virtual-camera.nix

@@ -0,0 +1,22 @@
+{ pkgs, lib, config, ... }:
+with lib;
+
+let cfg = config.hardware.virtual-camera;
+
+in {
+  options.hardware.virtual-camera = {
+    enable = mkEnableOption "Enable the virtual camera";
+  };
+
+  config = mkIf cfg.enable {
+    boot = {
+      # Virtual Camera/Mic
+      kernelModules = [ "v4l2loopback" "snd-aloop" "sg" ];
+      extraModulePackages = with config.boot.kernelPackages;
+        [ v4l2loopback.out ];
+      extraModprobeConfig = ''
+        options v4l2loopback exclusive_caps=1 card_label="Virtual Camera"
+      '';
+    };
+  };
+}