0.5.5 Content update pt 2

Content update part 2: Items and rooms

New stuff!

-2 new common items

-1 new rare item

-1 new boss item

-placeholder sounds

-REWORKED SHOP AND ITEM ROOMS

--item rooms let you pick between 2 items

--shops now don't restock automatically, but instead do it when you press the yellow button (costs 5 coins)

-reworked room layouts (what do people think)

-bugs?

-note: one of the new items is useless if you take the piercing boss item, this will be fixed in the next update

-note 2: items with no custom sprite have a blank item texture, check the discord for the blank texture if you want to help me with this