Neopixel driver for AVR mcu

Motivation

For AVR exist two library:

• With using extremely unstable features: https://github.com/devcexx/ws2812-avr
• With using only SPI: https://github.com/smart-leds-rs/ws2812-spi-rs

I'm focused on SmartLed trait implementation for AVR MCU (reference: https://github.com/devcexx/ws2812-avr).