Add Shopping cart workshop to main repo

[jdwilkin4]

We will add this workshop as is, including using the same ids.

https://www.freecodecamp.org/learn/javascript-algorithms-and-data-structures-v8/learn-basic-oop-by-building-a-shopping-cart/step-60

The test should be fine.
But if we need to do refactor, then that can be handled in 2025.

NOTE: This goes in the classes module, even though the link says OOP