Feature request: Allow users to enable GFM syntax highlighting in posts/pages plain text editor

[foliovision]

We write in Markdown via Parsedown with Markdown Extras and in our WordPress plain text editor for posts and pages would desperately like to be able to enable GFM syntax highlighting.

Your default settings aren't bad as you do pick up WordPress shortcodes which means quite a bit of Markdown syntax does get highlighted:

As you can see part of Markdown link syntax is highlighted, as are footnote links. With the HTML highlighting, Current syntax highlighting is a lot better than nothing.

PS. I'd be very interested in talking to someone from the HESH project who could create a custom version of HESH for us to integrate in our Parsedown plugin which would only work on plain text editor and would enable GFM by default and would allow us to keep a limited version of the settings off the screen and on a standard settings screen (in our software we prefer intelligent defaults than too many choices). This would of course be paid work. I can be contacted at alec at Github username + .com