Gentleman v1.4.2

This update adds custom theme support and improves the Settings menu layout.

Changelog

Added custom .json theme support.
Added a built-in Default theme that is always available.
Added a themes folder where users can place their own theme files.
Added simple user-facing theme color fields for menu, background, highlight, and text colors.
Reorganized Settings:
- Moved Menu Size and Auto Hide Menu to Display
- Moved Wallpapers to Display
- Renamed Menu to Menu Items