add js

data/flake/js/default.nix

@@ -0,0 +1,25 @@
+{
+  description = "Node.js and JavaScript development environment";
+
+  inputs = {
+    nixpkgs.url = "github:NixOS/nixpkgs/nixos-unstable";
+  };
+
+  outputs = { self, nixpkgs }:
+    let
+      supportedSystems = [ "x86_64-linux" "aarch64-linux" "x86_64-darwin" "aarch64-darwin" ];
+      forEachSupportedSystem = f: nixpkgs.lib.genAttrs supportedSystems (system: f {
+        pkgs = import nixpkgs { inherit system; };
+      });
+    in
+  {
+    devShells = forEachSupportedSystem ({ pkgs }: {
+      default = pkgs.mkShell {
+        packages = with pkgs; [
+          nodejs
+          nodePackages.npm
+        ];
+      };
+    });
+  };
+}