Since Raw post button is such a hit, see the hearts, in the same light here is another problem that as a site admin I am constantly writing a reply to users to explain how to use Markdown.
As I have never written a theme or plugin yet I don’t know which one would be needed to solve this problem but hope it is a theme.
When editing a post, in the tool bar should be a ? icon or something that takes one either to a page that explains Markdown on the site, or a popup that shows the Markdown.