Some of us begged for this in the early days after the migration. I don’t know if that ever happened.
Here are some helpful links: One to GreysonCarlisle’s tutorial thread (this is the one that we need to have pinned!) and one to an external page full of Markdown codes.
You can save bookmarks to both of them in your browser, as I have done.
GreysonCarlisle’s thread. – Very extensive and detailed!
Markdown Reference page. – Just some basics, but includes links to additional information.