I think I did.
It was easy, and it was pretty accurate when it said:
"If you have ten minutes, you can learn Markdown!"
I guess Keybase doesn't do the same style block quotes as the tutorial site, but I guess that's ok, since I don't really do that many quotes, and I'm sure I can fancy things up if I need to.
I think I can also put a picture here, let's see if this works.
Look at how cute my cat is!
Anyway, time to go see how it looks. Not too bad as a very basic web page.