Yes it means you don’t have to fork a theme. As long as the theme is available as a Ruby gem you can use remote_theme.
All it’s doing is pulling down the theme files (layouts, includes, CSS, etc) so you don’t have to manage them. Everything that applies for Gem-based themes applies for those assigned with remote_theme. The only difference being how you “install” them.
I forked your repo and played around with it, I get build errors for that theme, I think maybe it is not a proper gem based theme?
If I use one of mademistakes themes it works fine.
I don’t use gem based themes so I don’t know enough to be able to tell what is wrong with it, I would open up an issue on that repo and see if anyone is able to use it as a remote theme.
Again i don’t use gem based themes so it could easily be something I am doing wrong, I also find it a little interesting that it looks like the theme is working for you, just that you are getting build errors now so it is not updating any changes. hmmmm maybe I’ll keep trying.
if you are just starting out / learning I would recommend you fork a non theme based site to see how everything works, I think the themes hide a lot of the nuts and bolts and make it more mysterious than it really is.
The first post “Bookofmozilla” doesn’t have any formatting because you don’t have any YAML Front Matter. You’ll want to add a layout and title like so:
title: "The Book of Mozilla"
You can go ahead and remove the #The Book of Mozilla line in your body content as it’s not needed.
I suggest you give Jekyll’s documentation a good read to learn the basics. Then read the theme’s docs to understand how they set things up. Their README doesn’t have much info but looking through their demo site tells you more about how to get started.