Added Contributing Guidelines to repo.
Added Contributing Guidelines to repo.

vlesierse/cake,marcosnz/cake,phenixdotnet/cake,devlead/cake,UnbelievablyRitchie/cake,ferventcoder/cake,Julien-Mialon/cake,adamhathcock/cake,cake-build/cake,phrusher/cake,mholo65/cake,DixonD-git/cake,danielrozo/cake,phrusher/cake,thomaslevesque/cake,RehanSaeed/cake,patriksvensson/cake,Invenietis/cake,cake-build/cake,adamhathcock/cake,devlead/cake,wallymathieu/cake,gep13/cake,michael-wolfenden/cake,patriksvensson/cake,robgha01/cake,thomaslevesque/cake,Invenietis/cake,RehanSaeed/cake,Sam13/cake,jrnail23/cake,os-alan/cake,daveaglick/cake,yvschmid/cake,mholo65/cake,RichiCoder1/cake,daveaglick/cake,robgha01/cake,Julien-Mialon/cake,RichiCoder1/cake,marcosnz/cake,jrnail23/cake,yvschmid/cake,ferventcoder/cake,phenixdotnet/cake,DavidDeSloovere/cake,michael-wolfenden/cake,danielrozo/cake,Sam13/cake,vlesierse/cake,SharpeRAD/Cake,gep13/cake,SharpeRAD/Cake,UnbelievablyRitchie/cake,andycmaj/cake,andycmaj/cake