This is a data type for items that are for sale in the in game store. You would only use this inside of the useStore function to create the store items.
string - The relative path to an image.
string - The name of the item.
string - What customers use to pay with, this could be a resource.
string - How much customers pay.
string - The server action for buying the item. This needs to match the same action that you put on the server.
new g.StoreItem( 'pickaxe.png', 'Pickaxe', 'stone', 50, 'createPickaxe' )