Markdown help link should open on a new tab

The issue editor has "Markdown supported" icon in the bottom right corner. Clicking on this open the markdown help page - and cancel editing. (You can continue editing when you got back)

I think most users does not expected this. The purpose of using the help link is to look up a markdown format, so you probably do it while editing and does not want switch back and forth to the markdown help.

Requested Change: The markdown help page should open in a new tab.