WYSIWYG does not refer to the icons in the toolbar, but rather the text itself. This is not WYSIWYG because when I make something bold, I see a bunch of asterisks around it.

Still a cool project, but someone who does not understand markdown would wonder why pressing the heading button makes my text into a hashtag instead of making it bigger.

You see _ text _, but instead of 2 underscores you get formatted text. That's a definitional violation of WYSIWYG editing style