Added flake.nix for Nix Users

Provides a devShell to for development Environment

flake.lock

@@ -0,0 +1,27 @@
+{
+  "nodes": {
+    "nixpkgs": {
+      "locked": {
+        "lastModified": 1777578337,
+        "narHash": "sha256-Ad49moKWeXtKBJNy2ebiTQUEgdLyvGmTeykAQ9xM+Z4=",
+        "owner": "NixOS",
+        "repo": "nixpkgs",
+        "rev": "15f4ee454b1dce334612fa6843b3e05cf546efab",
+        "type": "github"
+      },
+      "original": {
+        "owner": "NixOS",
+        "ref": "nixos-unstable",
+        "repo": "nixpkgs",
+        "type": "github"
+      }
+    },
+    "root": {
+      "inputs": {
+        "nixpkgs": "nixpkgs"
+      }
+    }
+  },
+  "root": "root",
+  "version": 7
+}

flake.nix

@@ -0,0 +1,30 @@
+{
+  description = "angestoepselt-homepage";
+
+  inputs.nixpkgs.url = "github:NixOS/nixpkgs/nixos-unstable";
+
+  outputs = { self, nixpkgs }:
+    let
+      systems = [ "x86_64-linux" "aarch64-linux" "x86_64-darwin" "aarch64-darwin" ];
+      forAllSystems = f: nixpkgs.lib.genAttrs systems (system: f nixpkgs.legacyPackages.${system});
+    in {
+      devShells = forAllSystems (pkgs: {
+        default = pkgs.mkShell {
+          packages = [
+            pkgs.nodejs_20
+          ];
+
+          shellHook = ''
+            echo "Installing npm dependencies"
+            npm install
+
+            echo ""
+            echo "Run the site:"
+            echo "npm run build:styles"
+            echo "SITE=angestoepselt npm run dev:site"
+            echo "SITE=coderdojo npm run dev:site"
+          '';
+        };
+      });
+    };
+}