It does support Github Flavoured Markdown and has a preview mode built in, no extension needed.
Re:Visual Studio Code 1.6
by jason_slack on Tuesday October 11, 2016 @07:39AM
(#12683384)
Awesome. Thank you. I haven't tried VSCode since before 1.0.
Downloading now. I'd love to get away from Atom.
I'm using Atom as it has some nice plugins. But I tend to preview my markdown in Marked 2 anyway.