feat: setup base

modules/flake/overlays.nix

@@ -0,0 +1,28 @@
+{
+  inputs,
+  withSystem,
+  ...
+}:
+{
+  flake.overlays = {
+    modifications = final: prev: {
+      tnvim = inputs.tnvim.packages.${prev.stdenv.hostPlatform.system}.default;
+    };
+
+    stable-packages = final: _prev: {
+      stable = import inputs.nixpkgs-stable {
+        system = final.stdenv.hostPlatform.system;
+        config.allowUnfree = true;
+      };
+    };
+  };
+
+  perSystem =
+    { system, ... }:
+    {
+      _module.args.pkgs = import inputs.nixpkgs {
+        inherit system;
+        overlays = builtins.attrValues inputs.self.overlays;
+      };
+    };
+}