feat: Add nixos configuration flake

nix/flake.nix

@@ -0,0 +1,31 @@
+{
+  description = "Marm's NixOS flake";
+
+  inputs = {
+    nixpkgs.url = "github:nixos/nixpkgs?ref=nixos-unstable";
+    nur = {
+      inputs.nixpkgs.follows = "nixpkgs";
+      url = "github:nix-community/NUR";
+    };
+  };
+
+  outputs = { self, nixpkgs, nur, ... } @ inputs:
+  let
+    inherit (self) outputs;  # outputs = self.outputs;
+  in
+  {
+    nixosConfigurations = {
+      lamarr = nixpkgs.lib.nixosSystem {
+        specialArgs = {
+          inherit inputs outputs;
+
+          hostname = "lamarr";
+        };
+        modules = [
+          ./configuration.nix
+          nur.modules.nixos.default
+        ];
+      };
+    };
+  };
+}