Adding a new item?

[Wesnc]

I just realized that Don't Starve uses lua and so much can be done with it by the looks of it.

How would I go about adding a new item? Say a bigger backpack?

I tried to add the recipe, adding the item descriptions and I copied the backpack prefab and renamed it but as Soon as I pressed the Survival tab it crashed the game.

I haven't seen any threads about adding items or anything so I ask, how can this be done?