Move all files to building-static-websites-sculpin/demo/

building-static-websites-sculpin/demo/flake.nix

@@ -0,0 +1,22 @@
+{
+  inputs.nixpkgs.url = "github:nixos/nixpkgs/nixos-unstable";
+
+  outputs =
+    { nixpkgs, ... }:
+    let
+      system = "x86_64-linux";
+      pkgs = import nixpkgs { inherit system; };
+    in
+    {
+      devShells.${system}.default =
+        with pkgs;
+        mkShell {
+          buildInputs = [
+            php83
+            php83Packages.composer
+          ];
+        };
+
+      formatters.${system} = pkgs.nixfmt-rfc-style;
+    };
+}