I can type text, mark it, click "B" for bold and it works. This is WYSIWYG minus images.

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.

I see both. It's bold and has asterisks around the bolded text.

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