Can you help implement the Arduino board?

Question

Arduino

On the Internet, I came across the Pi0cket project. In fact, this is a micro-keyboard with a raspberry pi zero and a display.
Here you need to make a micro keyboard in which arduino will act as a controller (well, or throw controllers that you can buy in St. Petersburg), it must be connected via usb.
Keys from tact buttons (four pins. I just had a lot of them lying around).
qwerty layout, but not a full keyboard.

Answer 1

Arduino Leonardo

Answer 2

Well, I can do this crap on any MK. I just don't understand why. The price will be about the same, but the possibilities are disproportionately smaller.