Reworked some card grid component logic

I heard it’s better to create an array of the props rather than an array of the cards, so after struggling a bit I got to do it the conventional way with array mapping!
Not entirely sure what the individual mapping keys are for but I will look more deeply into that. It says online that you have to keep keys stable so that React knows which item you’re referencing but don’t totally understand why it would need to know that lol