[DOCS] @daffodil/cart Standardized Documentation

[xelaint]

📄 Documentation Request

What were you doing?

Documentation for packages are not uniform and extensive enough.

Expected behavior

• Overview: What is the package's purpose? How do I install and use this package?
  • Short paragraph explaining package's purpose
  • Installation
• Usage
  • How do I retrieve the current user's cart?
  • How do I change the current cart storage mechanism for the user?
  • How do I add items user's cart?
  • How do I remove items from a user's cart?
  • How do I update the item quantity in my cart?
  • How do I change the cart driver?
  • How do I apply a promotion to my user's cart?
  • Updating a user's billing and shipping address at the same time
  • Applying a payment to the cart (probably just redirect to a payment guide)
• State
• Drivers
  • Hubspot
• Configuration
• Testing

Existing Documentation

Environment

Daffodil version: X.Y.Z
Angular version: X.Y.Z 

 
For Tooling issues:
- Node version: XX  
- Platform:  

Others:

[damienwebdev]

@griest024 can you think up some common tasks you can do with the cart package?

• How do I retrieve the current user's cart?
• How do I change the current cart storage mechanism for the user?
• How do I add items user's cart?
• How do I remove items from a user's cart?
• How do I update the item quantity in my cart?
• How do I change the cart driver?
• How do I apply a promotion to my user's cart?