app_name for help output is a constant (for easy testing)
app_name for help output is a constant (for easy testing)

moses-gangipogu/github-markdown-toc,dushaobindoudou/github-markdown-toc,ekalinin/github-markdown-toc,vdaubry/github-markdown-toc,WHenderson/github-markdown-toc,lolgear/github-markdown-toc,norux/github-markdown-toc,Ever-Never/github-markdown-toc