feat: add createScript wrapper also stolen from @ivarwithoutbones

pkgs/createScript/default.nix

@@ -0,0 +1,40 @@
+{
+  lib,
+  runCommand,
+  makeWrapper,
+}:
+
+# A function which creates a shell script with optional dependencies added to PATH.
+
+name: src:
+{
+  dependencies ? [ ],
+  ...
+}@attrs:
+
+runCommand name
+  (
+    {
+      inherit src;
+      nativeBuildInputs = lib.optionals (dependencies != [ ]) (attrs.nativeBuildInputs or [ ]) ++ [
+        makeWrapper
+      ];
+
+      meta = {
+        mainProgram = name;
+      } // attrs.meta or { };
+    }
+    // (builtins.removeAttrs attrs [
+      "nativeBuildInputs"
+      "meta"
+    ])
+  )
+  ''
+    mkdir -p $out/bin
+    install -Dm755 $src $out/bin/$name
+    patchShebangs $out/bin/$name
+
+    ${lib.optionalString (dependencies != [ ]) ''
+      wrapProgram $out/bin/$name --prefix PATH : ${lib.makeBinPath dependencies}
+    ''}
+  ''