MyDimension

{
  "type": "mydimension:nature_mind",
  "generator": {
    "type": "minecraft:flat",
    "settings": {
      "biome": "mydimension:nature_mind",
      "features": true,
      "lakes": false,
      "layers": [
        {
          "block": "minecraft:stone",
          "height": 50
        },
        {
          "block": "minecraft:dirt",
          "height": 9
        },
        {
          "block": "minecraft:grass_block",
          "height": 1
        }
      ],
      "structure_overrides": []
    }
  }
}