Minecraft wiki entry for Configured_feature, associated text: vegetation_patch
 surface: The surface to place on. One of floor, or ceiling
 depth: Int provider between 1 and 128.
Int provider[show]
 vertical_range: Value between 1 and 256.
 extra_bottom_block_chance: Value between 0 and 1.
 extra_edge_column_chance: Value between 0 and 1.
 vegetation_chance: Value between 0 and 1. The chance that a vegetation feature will be placed, is evaluated for each block.
 xz_radius: Int provider. The radius of the patch.
Int provider[show]
 replaceable: A block tag specifying what blocks this feature can replace.
 ground_state: The block to use for the ground of the patch.
Block state provider[show]
 vegetation_feature: The placed feature to place on top of the patch.