feat(bsp): Adafruit TRRS Trinkey

[QuantumEF]

Summary

WIP: Add board support package for the Adafruit TRRS Trinkey
board

Checklist

• All new or modified code is well documented, especially public items
• No new warnings or clippy suggestions have been introduced - CI will deny clippy warnings by default! You may #[allow] certain lints where reasonable, but ideally justify those with a short comment.
• test blinky_basic example
• test usb_echo example
• test usb_hid example
• Make the USB examples using safe rust
• See if timers in the "blinky_embassy" example can be simplified
• test I2C example
  • Why does it compile despite peripherals.sercom2 not seeming to exist?
• test PWM example
• track Add PTC support for SAMD11 and SAMD21 #420
• test UART example
• write a "plug detection method"
• make sure example use said plug detection.

If Adding a new Board

• Board CI added to crates.json
• Board is properly following "Tier 2" conventions, unless otherwise decided to be "Tier 1"