qmk_firmware/keyboards/boardsource/lulu/avr/keyboard.json

{
  "build": {
    "lto": true
  },
  "development_board": "elite_c",
  "matrix_pins": {
    "cols": ["F6", "F7", "B1", "B3", "B2", "B6"],
    "rows": ["C6", "D7", "E6", "B4", "B5"]
  },
  "split": {
    "soft_serial_pin": "D2"
  },
  "ws2812": {
     "pin": "D3"
  },
  "encoder": {
    "rotary": [
      {"pin_a": "F4", "pin_b": "F5"}
    ]
  }
}