The Embed.ly integration is undoubtedly a winner and embedding code from GISTS in GitHub is the 'right' way.
BUT, as people concerned with actually teaching others about code we really need a quick and easy way enter single lines or blocks of monospaced text.
Strangely one of my colleagues got this to working as you can see here in this actual screenshot from editing a course, but he can't remember how!
Basically, please give us away to paste lines like that in quickly, or better still, give us 'monospaced' formatter in the toolbar and we're good!
WITHOUT IT, my technical authors who will always needs to add in liners as above...
brew install php71
...are finding it very limited.
Once again, as you can see from the above screenshot, my colleague actually achieved it!