The guide is concise and well written. I like how it builds in the same sequence I blogged about: HTML, CSS, JS, and introduces each in a small way with links for further study. I like how it starts with a static site, but I think the end of the guide could include an example for server side processing. It was clever to use 3rd party example like search with fetch, but an example with a small JS backend to process a form and persist to a database / file would tie it together. It sounds like server-side is out of scope for the framework, so perhaps a few examples of small backends and how to plug in?

When I was reading the header/footer section, it reminded me of this issue to push for first-class includes in web platform https://github.com/whatwg/html/issues/2791