Add GitHub-Flavored-Markdown to supported languages
Add GitHub-Flavored-Markdown to supported languages

rcuvgd/brackets-outline-list,pelatx/brackets-outline-list,pelatx/brackets-outline-list,BernsteinA/brackets-outline-list,Hirse/brackets-outline-list,BernsteinA/brackets-outline-list,pelatx/brackets-outline-list,rcuvgd/brackets-outline-list,Hirse/brackets-outline-list,Hirse/brackets-outline-list,onesfreedom/brackets-outline-list,onesfreedom/brackets-outline-list,rcuvgd/brackets-outline-list,Hirse/brackets-outline-list,pelatx/brackets-outline-list,BernsteinA/brackets-outline-list