Add common microcontrollers

[duckinator]

Microcontroller families to include:

• [ ] AVR family
  • [x] ATtiny85
  • [x] ATtiny2313
  • [x] ATMega328 + ATMega328p
• [ ] Raspberry Pi Pico
• [ ] MOS Technology 6502 family
  • [ ] 6502
  • [ ] TODO: determine other variants to include
  • [ ] TODO: add support ICs here
• [ ] Zilog Z80
• [ ] PIC family
• [ ] 8051 family
• [ ] TI MSP430
• [ ] ESP32 family
• [ ] STM32 family
• [ ] ARM32 family

This list is incomplete, and other families or specific ICs not listed here are still welcome!

Part of #112.