[MC-130826] NBT support should be added on Custom Crafting recipes

It is very disappointing that you did not create NBT support for custom recipes. If you add it on later snapshots and on the full release, it would be awesome!

I'm trying to create a recipe of a Written Book recipe with text inside, but because of no NBT support, it is not possible:

{
    "type": "crafting_shapeless",
    "ingredients": [
        {"item": "minecraft:book"},
        {"item": "minecraft:iron_ingot"}
    ],
    "result": {
        "item": "minecraft:written_book"
    }
}

compared to if you add NBT support in the later 1.13 snapshots and the future release, it would be possible!

{
    "type": "crafting_shapeless",
    "ingredients": [
        {"item": "minecraft:book"},
        {"item": "minecraft:iron_ingot"}
    ],
    "result": {
        "item": "minecraft:written_book",
        "nbt": "{title:\"Hello!\",author:\"Boyrex\",pages:[\"[\\"\\",{\\"text\\":\\"Haha!\\"}]\"]}"
    }
}

I want you to see you add this awesome feature in the full release and in the later snapshots. Once again, thanks!