targets: Add Shrike Lite board

[YajTPG]

Hello,

Pinouts: https://vicharak-in.github.io/shrike/shrike_pinouts.html

Also a quick question, while adding documentation for the board can I link users outside the tinygo-org repos or is it preferred to add the code to the doc itself?
I wanted to add the process of flashing the FPGA to the doc: https://github.com/YajTPG/shrike_go/blob/master/shrikeflash.go

Thanks!