Add a configuration option to specify crops from other mods and allow them to spawn in the world like TFC crops.

A few things:

• This should be doable via addons already.
• Providing a scriptable / json based configuration for this will likely require some significant redesigning if we are to do this properly.
• I would rather this was implemented in a 1.14-compatible method, which would avoid the use of craft tweaker (and preferably do something similar to how ore generation is handled, which will be easily portable to a 1.14 datapack system.)

a year later,

plus the fact that this will be automatic in 1.16.2 because all of world gen has become a data pack, this isn't going to be done in 1.12.