You can create a content type for any type of content. Really! The most obvious one is blogposts, but it could as well be documentation, a changelog or a knowledge base.
When getting started, you probably go for a content type you already have on your site, like a blog. But you could as well set up a completely new content type.
You find the Set up content button when hovering over the sidebar. Choose it and the modal opens to help you set up a new content type.
If this is not your first content type, you notice some details like the repo and the framework are prefilled. This is because your site is set up when you added the first content type.
Something still unclear? Reach out to support.