flake: rework modules folder structure

modules/nixos/programs/niri.nix

@@ -0,0 +1,29 @@
+{
+  config,
+  lib,
+  pkgs,
+  ...
+}:
+{
+
+  options.settings.programs.niri = {
+    enable = lib.mkEnableOption "enables the niri window-manager";
+  };
+
+  config = lib.mkIf config.settings.programs.niri.enable {
+    programs.niri.enable = true;
+    programs.niri.package = pkgs.niri-unstable;
+
+    security.pam.services.swaylock = { };
+
+    environment.systemPackages = with pkgs; [
+      swayosd
+      fuzzel
+      alacritty
+      wl-clipboard
+      wayland-utils
+      libsecret
+      xwayland-satellite-unstable
+    ];
+  };
+}