Where to submit Github syntax highlighting error?

I found a problem with the Github syntax highlighting (basically ' is incorrectly parsed as the beginning of a character string, rather than as the transpose operator), but I cannot for the life of me figure out which is the correct library for which to submit a bug report. Could anyone point me to where that might be? Thanks!

AFAIK they use Linguist:

Thanks, that’s right I think, although on Linguist’s page it says “If you experience an issue with the syntax-highlighting on GitHub, please report the issue to the upstream grammar repository, not here”. Any idea what that is?

following the links on that page takes you to

Ha thanks, I missed the link a whole like 10 characters away from the quote I posted. That’s the one, thanks.