v0.02

This update modifies how rolling on cards works. Instead of being randomly assigned one power mod and one ability mod, you get a choice of two new mods as well as the option of keeping the mod which was previously on the card. 

You now also upgrade your cards exclusively in shops and card experience is no longer a thing. I made a shop always spawn just before the boss encounter. 

There are two new shard types, one of which deletes a card, and another which upgrades the tier of all modifications on the card. This should make getting desirable combinations easier overall!