Tweak that allows to define hotkeys that will swap to the specified item.

Without adding a new UI type, the only way to configure this I see is, similar to #315:
{hotkey} => {item_ids}

e.g. you could configure:

shift+t => minecraft:torch
shift+h => minecraft:diamond_hoe, minecraft:iron_hoe

with multiple values specified, it will just choose them in order of the list.