Co2mini

What's Changed
* 🔧 Modernize and cleanup by jerr0328 in https://github.com/jerr0328/co2mini/pull/2
* Bump actions/checkout from 2 to 3 by dependabot in https://github.com/jerr0328/co2mini/pull/3
* Bump actions/setup-python from 2 to 3 by dependabot in https://github.com/jerr0328/co2mini/pull/4
* 🔧 Improve udev/systemd and requirements by jerr0328 in https://github.com/jerr0328/co2mini/pull/5

**Full Changelog**: https://github.com/jerr0328/co2mini/compare/v0.2.0...v0.3.0

✨ Avoid flapping HomeKit alerts by clearing alert at different threshold
✨ Decrease update interval of HomeKit to reduce traffic

🐛 Fix startup issues
📚 Improve examples and instructions

🎉 Initial release on PyPi with large refactor to support HomeKit as well as Prometheus. Now much easier to install!