Open letter helps you make simple websites or pages just from a markdown file. You don't have to set anything up, just run npx open-letter and your website will be generated.
Yes, also this website is generated, just using the single command. All the menu, pages, etc, is just being created from markdown files and a few settings defined In these markdown files.
You can find the source code in Github all files used for this page, is the main README.md and the files in the /docs folder.