Controller support added

I've added basic controller support to the Windows and Linux (AppImage) versions of Sumash, my Shamus-inspired runner. Keyboard controls still work, but this version adds basic support for controllers like the XBOX 360 controller. I tested the game both on Windows 10 and Xubuntu 24.04 using the Logitech GamePad F310. (Note: I had to add libfuse2 support on Ubuntu 24.04 for any AppImages to work). Earlier versions seemed to just work. Have fun and please let me know if you enjoy the game!