chore(git): add a CONTRIBUTING.md
chore(git): add a CONTRIBUTING.md

nickgonzales/hyper,golddranks/hyper,Twey/hyper,yazaddaruvala/hyper,clatour/hyper,Twey/hyper,hyperium/hyper,mlalic/hyper,mikedilger/hyper,Keats/hyper,hyperium/hyper,fuchsnj/hyper,fengsp/hyper,softprops/hyper,hannobraun/hyper,tshepang/hyper,bonifaido/hyper,pyfisch/hyper,golddranks/hyper,nickgonzales/hyper,PeterReid/hyper,mre/hyper,achanda/hyper,jmmaranan/hyper,hannobraun/hyper,yangxingpping/hyper,mitsuhiko/hyper,erickt/hyper,tempbottle/hyper,tshepang/hyper,mlalic/hyper,markuskobler/hyper,reem/hyper,servo/hyper,golddranks/hyper,nstoddard/hyper,bheesham/hyper,nstoddard/hyper,peterhj/hyper,huonw/hyper,mneumann/hyper,tshepang/hyper,Ryman/hyper,lame-nickname/hyper,frewsxcv/hyper,youprofit/hyper,sfackler/hyper,hannobraun/hyper,yazaddaruvala/hyper,mfeckie/hyper,TimNN/hyper,markuskobler/hyper,ianks/hyper,manuel-woelker/hyper,Twey/hyper,rschulman/hyper,markuskobler/hyper,Keats/hyper,steveklabnik/hyper,fhahn/hyper,giftcards/hyper,Keats/hyper,nickgonzales/hyper,hyperium/hyper