Flake added

configuration.nix

@@ -5,6 +5,7 @@
     ./hardware-configuration.nix
     # Add further modules here later, e.g.:
     ./programs.nix
+    ./flake.nix
     # ./modules/nextcloud.nix
     # ./modules/wireguard.nix
     # ./modules/docker.nix

flake.nix

@@ -0,0 +1,16 @@
+{
+  description = "NixOS Konfiguration";
+
+  inputs = {
+    nixpkgs.url = "github:NixOS/nixpkgs/nixos-25.11";
+  };
+
+  outputs = { self, nixpkgs, ... }: {
+    nixosConfigurations.nixos = nixpkgs.lib.nixosSystem {
+      system = "x86_64-linux";
+      modules = [
+        ./configuration.nix
+      ];
+    };
+  };
+}