Item Collection

Item collection is a module that creates "bags", items that can hold other items.

• Bags can contain any "items" (including spells, feats, and other bags). Items can be added to a bag via drag and drop or the import button (which brings in the entire inventory). Items can be removed from a bag via drag and drop to a character inventory, bag, item directory or compendium according to permissions. Items can be exported to your inventory via buttons on the bag sheet.
• Bags have a capacity indicating how much they can hold. A capacity of 0 means are infinite. This can only be set by the GM. If you try and drop an from a bag or character inventory into a bag that is too heavy for the bag it will be added to your inventory instead.
• Bags can be set to a fixed weight (as used in the encumbrance calculation), think a bag of holding (capacity 500, fixed weight 15) or a mule (fixed weight 0, capacity 690).

https://foundryvtt.com/packages/itemcollection

This module is great and allows the creation of any item that can contain other items. I kept the default settings, but make sure the [sort bag contents] is checked if you want everything in alphabetical order.