I've definitely heard of it! Would I need to know Python well to use it? (Not opposed to getting better at Python, obviously, but just a consideration for my partner)
You only need to learn Python if you want to do back-end development. Templating, design, content etc don't require any Python skills - just as you don't need PHP skill to build sites in WordPress.
Yeah, this looks like a promising solution! I assume this means content creation occurs in the source code instead (not a showstopper, but a nice-to-have request from my friend)?