* 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
* Use fugit time types for SPI peripheral, update examples
* initial WIP
* fix CI build errors
* Use extension trait in examples
Co-authored-by: Jesse Braham <jesse@beta7.io>
