Added a customizable spawner to Minecraft that can spawn any entity.
If you're a modpack author, you might need him, and you can put him in your custom structure and have him spawn in the world so that when the player gets close to the specified range, he will detect and spawn any entity creature bosses you want.
In creative mode you can right-click to open its GUI where you can set up the content you need.
The detection mechanism will only detect players who are in spawn mode.
My other projects：bountifulbaubles-reforked trinkets-and-baubles-reforked exporbrecall bossspawner step-height forsaken-items
