Rework skal to be the shared nix-wrapper module

nix-wrapper/flake-template.nix

@@ -0,0 +1,39 @@
+{
+  description = "";
+
+  inputs = {
+    nixpkgs.url = "github:nixos/nixpkgs/nixos-unstable";
+  };
+
+  outputs = { nixpkgs, ... }:
+    let
+      systems = [ "x86_64-linux" ];
+    in
+      {
+        packages = nixpkgs.lib.genAttrs systems (system:
+          let
+            pkgs = nixpkgs.legacyPackages.${system};
+          in
+            {
+              # `derivation` may be filled out or switched
+              # to something like `pkgs.buildGoModule`
+              default = derivation {
+                src = ./SRC_PATH;
+              };
+
+              hello = pkgs.hello;
+            }
+        );
+
+        devShells = nixpkgs.lib.genAttrs systems (system:
+          let
+            pkgs = nixpkgs.legacyPackages.${system};
+          in
+            {
+              default = pkgs.mkShell {
+                packages = [];
+              };
+            }
+        );
+      };
+}