fix(HealthColors): Version 2.1.1 fixes multiple bugs

- Added version 1.7.1 sourced from Roll20 forums for selectable previous version.
- Fixed aura visibility threshold logic for tokens based on HP.
- Improved settings menu interaction after changes.
- Enhanced error handling for missing custom FX names.
- Refactored code for clarity and reduced complexity.
- Updated JSDoc comments for accuracy.
- Added new commands for FX management and settings visibility.
- Updated README with new command references and usage instructions.
- Updated script.json to reflect new version and authors.

Author: steverobertsuk