Changes every trainer except for the ones that are already on doubles or that have only 1 pokemon to doubles format.
This is for the people that don't want to go through the hassle of manually changing every trainer into a doubles trainer.
Download the datapack version and go into your world > datapacks folder, in there add a folder and name it. Then drop the contents of the zip file into said folder.
When you enter your world enable it by using the command /datapack enable "file/FOLDERNAME"
Enjoy!
I also allow usage of this datapack/mod in modpacks!
Credits & Rights to @hd42 for the Radical Cobblemon Trainers mod
