Changelog:
- Added difficulty ratings
- Added getting hints
- Added optional automatic pencil marks
- Added playing puzzles entered by player
- Added printing puzzles
- Added restarting puzzles
- Added support for Qt 6
- Improved new game interface
- Improved window spacing
- Refactored code
- Removed XPM icon
- Translation updates: Bulgarian, Lithuanian, Romanian, Russian, Telugu
Signed-off-by: Algent Albrahimi <algent@protonmail.com>