Adding libs and binaries

Adding Snazzy FM with DAC changes

Adding fix for facdrums

Updating building doc so R50 is now 47k

Update BUILDING.md

Adding alternative suggested building docs

Adding MCP4921 librar instructions to the repo

Changing exported bom CSV

Changing R50 to 47k to have better gain on output, this was corrected on the Schematics, Board, BOM list and Mouser Project link, also fix in the __dac.setGain(1);__ instruction of the DAC, to use 5v ref instead of 3.3v

Update BUILDING.md