Adafruit CH9328 UART to HID Keyboard Breakout

We love using chips with 'native USB' peripherals - that's the magic silicon that lets a microcontroller act like an HID keyboard or mouse or disk drive or MIDI synth. It's a standard addition on SAMD21, RP2040, and even the latest ESP32-S2 and ESP32-S3 boards. But what about when you have a classic ATmega328 Uno? or an original ESP32 or ESP8266? Maybe even a single-board computer like a Raspberry Pi? We would say "sorry...that's not possible" UNTIL NOW!