This is the first time that I have tried to make a mod for any game. I’m starting off with a simple “test mod” that adds one item, umbrella hats, and I can only retrieve the item through the debug menu. The problems that I am facing are: how to make the item spawn in certain structures (such as houses and clothing stores), how to set the spawn rate of the item, and how to add graphics to the item.
I don’t know more about modding than you do, but having looked through the files I think item_groups.json might be the one you’re looking to edit. It’s located inside \data\json. Use something like Notepad++ to open it and edit your item into the right place. There might be more files you need to edit so the item is actually in; I wouldn’t know, I’ve never done this either.
You must specify the item group it belongs to so it can spawn in houses and such will also enable the ability to doctate how common it would be.
About the graphics i am unsure,havent done it yet.