https://gist.github.com/notriddle/108fe255ffa9f490ed8ade262935eb53
jgm might want to change some of these to make pandoc's "gfm" mode match GitHub more closely.
left$\sqrt{2}$right
space $\sqrt{2}$right
left$\sqrt{2}$ space
space
"$\sqrt{2}$"
"
"$\sqrt{2}$ "
"
left
space
left
space
"
"
"
"
Pandoc “try” gfm mode of this same document