Abstract can be used on recipes (#41)

Author: TheGoatGod

documents/Updating_Legacy_JSON.md

@@ -122,8 +122,7 @@ If you're using linux, you're probably already familiar with the terminal. Use [
 # abstract, ident, and id
 `abstract` and `id`, are a specific type of `key` that tells the game the unique identifier of the item. Almost every top-level JSON `object` contains an an identifier and a `type`. `type` is an incredibly important `key` that tells the game how to handle the specific `key: value` pairs in the `object`.
 
-
-`abstract` can only be used on `type: TOOL`, `type: GENERIC`, `type: GUN`, `type: COMESTIBLE`, `type: BOOK`, `type: AMMO`, `type: PET_ARMOR`, `type: vehicle_part`, `type: BIONIC_ITEM`, `type: ARMOR`, `type: TOOLMOD`, `type: ENGINE`, `type: MONSTER`, `type: uncraft`, and `type: overmap_terrain`.
+`abstract` can only be used on `type: TOOL`, `type: GENERIC`, `type: GUN`, `type: COMESTIBLE`, `type: BOOK`, `type: AMMO`, `type: PET_ARMOR`, `type: vehicle_part`, `type: BIONIC_ITEM`, `type: ARMOR`, `type: TOOLMOD`, `type: ENGINE`, `type: MONSTER`, `type: uncraft`,  `type: overmap_terrain`, and `"type": "recipe",`.
 
 `abstract` creates a pseudo-item that only exists to be copied from and is discarded after JSON loading is complete. If you see it used outside of these fields, replace with `ident` or `id` as appropriate. For debugging purposes, it is preferable to not use `abstract` on types other than `type: overmap_terrain`. It can cause cascading errors that are impossible to find due to lack of item id and presence in the game. See [JSON Inheritance](https://github.com/CleverRaven/Cataclysm-DDA/blob/master/doc/JSON_INHERITANCE.md) for more information on how to use abstract.