Renamed `game` to `games` and `menu` to `menus`. Moved some functions from `engine/routines/` to their fitting subdirectories. Made two new subdirectories: * engine/rtc: Contains all RTC-related things. Menus, hardware, misc functions. * engine/items: Contains all item-related things. Pack, item effects, other item handlers.
engine/routines/ stores isolated out-of-context routines as individual files. It might be preferable later to append them to their related engine/ files in unique little SECTIONs, relying on the linkerscript to place them appropriately; or some other organization method. In the meantime, they're now easily findable apart from main.asm's other content.