Added #hacktoberfest mention to CONTRIBUTING.md
Added #hacktoberfest mention to CONTRIBUTING.md
HighSchoolHacking/GLS,HighSchoolHacking/GLS,HighSchoolHacking/GLS,general-language-syntax/GLS,general-language-syntax/GLS,general-language-syntax/GLS,general-language-syntax/GLS,general-language-syntax/GLS,HighSchoolHacking/GLS,HighSchoolHacking/GLS,HighSchoolHacking/GLS,general-language-syntax/GLS