Adds Contributing readme file: CONTRIBUTING.md
Adds Contributing readme file: CONTRIBUTING.md

file forked from Bitcoin core:  https://github.com/bitcoin/bitcoin/blob/
master/CONTRIBUTING.md

GregoryBetz/DarkSilk,GregoryBetz/DarkSilk,GregoryBetz/DarkSilk-Release-Candidate,GregoryBetz/DarkSilk,GregoryBetz/DarkSilk-Release-Candidate,GregoryBetz/DarkSilk,GregoryBetz/DarkSilk-Release-Candidate,GregoryBetz/DarkSilk-Release-Candidate,GregoryBetz/DarkSilk-Release-Candidate,GregoryBetz/DarkSilk-Release-Candidate,GregoryBetz/DarkSilk,GregoryBetz/DarkSilk