Custom world generation/template pool


 * The root tag
 * The namespaced id of the pool
 * Can set to another template pool, which generates when the original pool cannot generate at the end of all layers. Used in the vanilla datapack to generate the end of village streets, aka terminators in structure files.
 * A list of structures to choose from
 * How likely this element is to be chosen when using this pool
 * The properties of this element
 * The namespaced id of the structure to place
 * Can be rigid or terrain_matching
 * Can be minecraft:empty_pool_element to generate no structure, minecraft: feature_pool_element when feature is used, minecaft:list_pool_element when elements are used, and minecraft:legacy_single_pool_element or minecraft:single_pool_element when location is used
 * The namespaced ID of a processor if this is a string
 * A list of processors to use
 * The namespaced id of the processor to use
 * A list of structures to choose from
 * How likely this element is to be chosen when using this pool
 * The namespaced id of the structure to place
 * Can be rigid or terrain_matching
 * Can be minecraft:empty_pool_element to generate no structure, minecaft:list_pool_element when elements is used, and minecraft:legacy_single_pool_element or minecraft:single_pool_element when location is used
 * The namespaced ID of a processor if this is a string
 * A list of processors to use
 * The naemspaced id of the processor to use
 * Can be minecraft:empty_pool_element to generate no structure, minecaft:list_pool_element when elements is used, and minecraft:legacy_single_pool_element or minecraft:single_pool_element when location is used
 * The namespaced ID of a processor if this is a string
 * A list of processors to use
 * The naemspaced id of the processor to use
 * The naemspaced id of the processor to use