The ability to drag and drop a document to put this doc inside of a "file" so that this doc will be placed right next to one another under the same category. For example: dragging and dropping a doc inside of a page that will create a "file"

Branching off documents from the main source

Example:

Main Doc: Credit Cards

Docs inside of the file: Real Estate, Travel, Gas etc.

Another example:

Main Doc: Food

Docs inside of the file: Recipes, Meal Ideas, Nutrition, etc.