Update --allow-uploads help text in README
Merge pull request #853 from joscarsson/patch-1

Update --allow-uploads help text in README
Update README.md with installation instructions
Update README.md

GitHub Markup is now using asciidoctor
Merge pull request #859 from Mogztter/patch-1

Update installation procedure for AsciiDoc
add --mathjax [CONFIG] to inject root-repo/[CONFIG] file,

which is similar to the behavior of --css and --js.
CONFIG is "mathjax.config.js" by default.
Merge pull request #847 from hardywu/master

add --mathjax-config to inject root-repo/mathjax.config.js. Closes #842.