[QOL] default purchase item slot priority

Countless times, from game to game, I'm always forced to change the positions of items I buy from 1st slot to the others I more often use. I'm sure I'm not the only one and we could save a lot of time for players on this. Let players decide where the priority item positions are: for example, the default priority slot is the 1st one, I could change it to 6th so any item I buy will be automatically put into 6th slot unless it is occupied, I could set 2nd priority slot to the 4th slot and then the item would be put there if 6th slot were occupied. It's easy and we need it. Please, Riot.