[Suggestion] replace indexed-modded-items.json config with JsonDataLoader

[supersaiyansubtlety]

This would have several advantages:

• other mods could easily configure how their enchantments interact with Indexed just by putting a json file in the right directory
• JsonDataLoaders are per-world
• it would be easy to switch between different datapacks, effectively like 'config presets'. You could even have a few builtin resourcepacks that served as config presets

[supersaiyansubtlety]

Oh, and it would be easy for users to remove enchanting caps if the default values were in a builtin resourcepack.