* initial systimer impl
* Add systimer example
* Make Alarms real singletons
* Remove runtime Option, turn into compile error
* Make Systimer::now() not take self
* refactor shared alarm methods
* Implement esp32c3 delay with monotonic SystemTimer::now()
* Add extend systimer support to esp32s3 and add example
* systimer: esp32s2 support
- Add RMT output channel support for ESP32, ESP32-S2, ESP32-S3, ESP32-C3
- Add add RMT adapter for `smart-leds` crate
- Add example `hello_rgb` for ESP32-S2, ESP32-S3 and ESP32-C3 that either
drives one LED at the pin where a LED is located on the official devkits
- Add example `hello_rgb` for ESP32 that is driving a 12-element RGB ring.
