ghostwriter: add run-time dependencies to PATH

pkgs/applications/editors/ghostwriter/default.nix

···
-{ lib, stdenv, mkDerivation, fetchFromGitHub, qmake, pkg-config, qttools, qtwebengine, hunspell }:
+{ lib
+, stdenv
+, mkDerivation
+, fetchFromGitHub
+, qmake
+, pkg-config
+, qttools
+, qtwebengine
+, hunspell
+, cmark
+, multimarkdown
+, pandoc
+}:
 
 mkDerivation rec {
   pname = "ghostwriter";
···
   nativeBuildInputs = [ qmake pkg-config qttools ];
 
   buildInputs = [ qtwebengine hunspell ];
+
+  qtWrapperArgs = [
+    "--prefix" "PATH" ":" (lib.makeBinPath [ cmark multimarkdown pandoc ])
+  ];
 
   meta = with lib; {
     description = "A cross-platform, aesthetic, distraction-free Markdown editor";