Added support for Adafruit feather RP2040 DVI and WII-Classic controller by @PaintYourDragon
Bugfixes and enhancements:
- Removed unused mapper 6 to conserve memory #22 @kholia
- Now works with latest Pico SDK 1.5 #7 @kholia
- Added framerate toggle #20 @fhoedemakers
- Sound not working properly when using Pico SDK 1.5 #21 by @shuichitakano
- Moved nes rom flashing from menu.cpp to main.cpp in order to prevent locking up the Feather RP2040 DVI when using the WII-Classic controller. @fhoedemakers