message: Update NEWS for version 2.4
diff: +Version 2.4
  +-----------
  +
  +- Crowdin integration was greatly improved and now supports editing of any
  + kind of localization: files from Crowdin projects, not just POs.
  +- Improvements to editor user interface.
  +- [macOS] Fixes to light/dark mode switching.
  +
  +
  Version 2.3.1
  -------------
  