Un rec-ify derivation

default.nix

@@ -12,7 +12,7 @@ let
   gitignoreSource = pkgs.nix-gitignore.gitignoreFilterSourcePure (_: _: true);
 
 in
-pkgs.stdenv.mkDerivation rec {
+pkgs.stdenv.mkDerivation {
 
   name = "document";