Pawns now can have upgrades applied to them when purchased.

Refactored hard-coded setup of pieces, Moved preload of scenes from draw_pieces to ready(). player_gold now updates and dispalys with piece capture!

Changed shop to 3 items of each, added rarity tiers for items and upgrades. Shop is now kinda centered sometimes

Added gold display. Hides the board and pieces when shop is displayed.