add flake.nix

flake.nix

@@ -0,0 +1,39 @@
+{
+  description = "DWL Development Shell";
+
+  inputs = {
+    nixpkgs.url = "github:nixos/nixpkgs/nixos-25.05";
+  };
+
+  outputs = {nixpkgs, ...}: let
+    system = "x86_64-linux";
+  in {
+    devShells."${system}".default = let
+      pkgs = import nixpkgs {
+        inherit system;
+      };
+    in
+      pkgs.mkShell {
+        packages = with pkgs; [
+          # NativeBuildInputs
+          installShellFiles
+          pkg-config
+          wayland-scanner
+
+          # BuildInputs
+          libinput
+          libxcb
+          libxkbcommon
+          pixman
+          wayland
+          wayland-protocols
+          wlroots
+
+          # XWayland
+          libX11
+          xcbutilwm
+          xwayland
+        ];
+      };
+  };
+}