/customitem command to add items via resource packs

This would be syntaxed something like "/customitem [durability] [attackdamage] [NBT]. I.e. /customitem sword 1500 9 {Recipe:emeraldsword.json,ChestLoot:1,rarity:100}. Basically the way you work this out is:
•replace with sword, pickaxe, axe, shovel, hoe... In short every type of item in minecraft.
•replace [durability] with the numerical durability of the item IF IT HAS DURABILITY.
•replace [attackdamage] with the attack damage it deals. Only valid for swords and axes.
•NBTs are:
•ChestLoot: set to either 1 or 0. Controls whether or not the item generates in chests.
•Recipe: set to .json. Replace with the recipe name.
•rarity: set to a value from 1 to 1000. The higher the value, the rarer it is to find in naturally generated chests.

NOTE: [attackdamage] and [durability] tags are INVALID for blocks and some item types, ie hoes.
The possibilities of this are endless: It would allow map creators a much wider (possibly infinite) range of materials, blocks, items, etc, etc.