README.md

This is the PicoSystem verson for Catacombs's Pokitto version created by Jhhoward

(original code: https://github.com/jhhoward/Catacombs-Pokitto )

Added sound volume setting at title page Optimized the 120*120 ARGB4444 display mode on Picosystem

I hacked the default audio callback function and add a new simple callback to porcess the tones sequence.