feat: add direnv + nix

.envrc

@@ -0,0 +1,2 @@
+watch_file flake.lock
+use flake

.gitignore

@@ -2,3 +2,4 @@
 .godot/
 /android/
 dist/
+.direnv/

flake.lock

@@ -0,0 +1,27 @@
+{
+  "nodes": {
+    "nixpkgs": {
+      "locked": {
+        "lastModified": 1737469691,
+        "narHash": "sha256-nmKOgAU48S41dTPIXAq0AHZSehWUn6ZPrUKijHAMmIk=",
+        "owner": "nixos",
+        "repo": "nixpkgs",
+        "rev": "9e4d5190a9482a1fb9d18adf0bdb83c6e506eaab",
+        "type": "github"
+      },
+      "original": {
+        "owner": "nixos",
+        "ref": "nixos-unstable",
+        "repo": "nixpkgs",
+        "type": "github"
+      }
+    },
+    "root": {
+      "inputs": {
+        "nixpkgs": "nixpkgs"
+      }
+    }
+  },
+  "root": "root",
+  "version": 7
+}

flake.nix

@@ -0,0 +1,40 @@
+{
+  description = "Simple shell for my test game";
+
+  # Flake inputs
+  inputs = {
+    nixpkgs.url = "github:nixos/nixpkgs/nixos-unstable";
+  };
+
+  # Flake outputs
+  outputs = { self, nixpkgs, ... }:
+    let
+      # Systems supported
+      allSystems = [
+        "x86_64-linux" # 64-bit Intel/AMD Linux
+        "aarch64-linux" # 64-bit ARM Linux
+        "x86_64-darwin" # 64-bit Intel macOS
+        "aarch64-darwin" # 64-bit ARM macOS
+      ];
+
+      # Helper to provide system-specific attributes
+      forAllSystems = f: nixpkgs.lib.genAttrs allSystems (system: f {
+        pkgs = import nixpkgs { inherit system; };
+      });
+    in
+    {
+      # Development environment output
+      devShells = forAllSystems ({ pkgs }: {
+        default =  pkgs.mkShell {
+          # The Nix packages provided in the environment
+          packages = (with pkgs; [
+            onefetch
+            godot_4
+          ]);
+          shellHook = ''
+            onefetch
+          '';
+        };
+      });
+    };
+}