[Demo] Half price for the 2nd item and beyond

This is a demo product that implements a discount campaign of "Half price for the 2nd item and beyond" using RuffRuff Order Bonus.

Depending on the quantity of this item in the cart, the behavior will be as follows:

• 1 item → No discount
• 2 items → 1 item at half price
• 3 items → 2 items at half price
• 4 items → 3 items at half price
• 5 items → 4 items at half price