PR #1441 was meant to address:

1. Lack of up-to-date offline documentation shipped with a Bazzite image.
2. Adding tooling to progressively moving documentation from Discourse to GitHub (if wished so).

Which was accomplished:

1. PDF generation out of documentation, which is then downloaded and added in the image build action (feat: Add offline documentation #1530).
2. Adding fetch_discourse_md.py, a script that facilitates scrapping of Discourse pages, both automatically by mdbook and contributors who wish to transcribe to a markdown file in GitHub.

It works, but would come to face several limitations imposed by mdbook:

1. MdBook ecosystem is written in Rust, which add complexity to develop preprocessors in simpler languages (ex.: python).
2. Related to limitation 1, plugin ecosystem is far more scarce, increasing the amount of self-developed solutions.
3. The current translation plugin (mdbook-i18n-helpers) is far too complex for translators, as uses Gettext. Not a bad tool, but far too overkill for our purpose.
4. Part of limitation 3, increased workarounds to deal with the default build output file layout, which can be potentially prone to errors.

Thus, MkDocs enters in scene:

1. Written in Python, far more populated plugin ecosystem.
2. Plugin API is way friendlier with hooks.
3. Less complex translation with mkdocs-static-i18n, using markdown files like article.es.md instead of using Gettext.

Not only that, but we replace the PDF generation with a locally hosted version of the documentation, which can be served with python -m http.server (documentation shortcut handles this).
Far more friendly for Steam Game Mode users, as they can then access from Steam builtin web browser.