- The GPIO module uses type-level programming now
- Implementation heavily based on the ATSAMD GPIO HAL:
https://docs.rs/atsamd-hal/0.13.0/atsamd_hal/gpio/v2/index.html
- Changes to API, but no passing of peripheral references necessary
anymore. All examples and tests updated accordingly
- Clock module to set and retrieve system clock which can have
varying frequencies. Also allows enabling peripheral clocks
- Prelude updated
- Common time types added, based on stm32f1xx HAL implementation
- Basic timer implementation added
