They're just templates. I think. You need some additional software, because they're set up to store a bunch of stuff and talk to each other locally, and you probably want command line experience.
I'm going to check with my family sysadmin (dad) about this before I go exploring much further. At the moment, I've moved away from Jekyll because I don't want to be tied to GitHub. I'm now looking at Eleventy, one of the recommendations for building a digital garden with a bit of code.