Adding an item is the main feature of your inventory. Items are used to store information and the most pertinant variables
around the items in your system and act as the foundation of all other aspects and features of this system. To create an Item
the 4 most important fields you need is the barcode (this is the unique number the item is tracked under), a name, an item type,
and finally a subtype.
There are two item types of items you can create:
Single Item - These are the bare bone item as you might think it to be. Its a barcode that gets moved about your system and tracked by that
barcode.
Linked Item - Linked Items are a more advanced feature that allows you to chain together barcodes into one. Whenever one of those barcodes
are transacted on it is instead replaced with its linked barcode. This allows you to chain together the same types of items together if you want.
I.E. you have multiple barcodes for Chicken Noodle Soup and want them all to be the same item instead of seperate items in your system.