[1.5pt] Implement methods in Genre class - Team member #2

[AndreaM2429]

Implement methods:

• add_item method in the Genre class
  • should take an instance of the Item class as an input
  • should add the input item to the collection of items
  • should add self as a property of the item object (by using the correct setter from the item object)
• The following options should be available:
  • List all genres (e.g 'Comedy', 'Thriller')