thag_styling 0.2.1

Terminal styling system with theme support and color detection for thag_rs
Documentation
## Notes for preparation of README.md

- Advocate for thag_styling but keep it factual and restrained.

Topics:

- Need to explain purpose / USP

  - Bring themed colours and styles to your application, ensuring a consistent and visually appealing user interface.

  - Create terminal themes from thag_styling themes for virtually all terminal emulators.

  - Create original themes from images

- Features

    - Generate themes from images - fine tuning and quality

    - Cross-platform support for TrueColor, 256-color and basic 16-color terminal emulators

    - List of supported terminals

    - Terminal detection capabilities

    - Tools in thag_rs

      - thag_alacritty_add_theme

      - thag_gen_terminal_themes

      - thag_image_to_theme

      - thag_mintty_add_theme

      - thag_palette_vs_theme

      - thag_show_themes

      - thag_sync_palette

      - thag_show_themes

      - thag_winterm_add_theme

  - thag_rs/demo scripts:

      - styling_demo.rs

      - styling_migration_guide.rs

      - truecolor.rs

- Representative gallery

- How-to

    - Per thag_styling/INTEGRATION_QUICK_START.md - ensure it's up to date.

    - Add in new macro set_verbosity and new fn init_verbosity (both re-exported from thag_common)

    - How to install thag_rs tools.