Interestingly, the 10-lines-of-basic competition, which has been running the last 15 years (https://itch.io/profile/bunsen), has this covered in the rules:

15. If the game is controlled with the keyboard, use "O" for left, "P" for right, "E" for up and "D" for down if possible; this takes into account the most important keyboard layouts (no disadvantages for emulator users with QWERTZ, QWERTY or AZERTY keyboards)