How I package it into a format suitable for Github Page
Hello MaHe,
Raneto is not designed for static sites currently (GitHub Pages, S3). It relies on a backend to render the Markdown and allow for editing.
Instead, you may consider git-based sites like Jekyll (Ruby) or Hugo (Golang) that generate HTML files. You can edit your files in GitHub's UI and set up automation to re-generate the HTML files, updating your site. https://docs.github.com/en/pages/setting-up-a-github-pages-site-with-jekyll
On further thinking, it should be straightforward to add an option for static-site generation. Also related to #383 because Netlify works similarly to GitHub Pages. It does not exist today, but I'll re-open this for consideration in the future and contributions for others