zmk/app/boards/nicekeyboards/nice_nano/board.yml

board:
  name: nice_nano
  vendor: nicekeyboards
  socs:
    - name: nrf52840
  revision:
    format: major.minor.patch
    default: 2.0.0
    revisions:
      - name: 1.0.0
      - name: 2.0.0