Sitemap generation is now independent from the navbar generation, and
it will be added to the navbar only once the navbar has been created.
Also, better style for code.
Dart is now upgraded to version 2.8
Any change in dependencies or Dart tooling won’t trigger Docker to
reinstall anything Ruby-related in the image afterward
Name of the Dart package and its homepage were changed, forgot to do
that
Table of content was made unavailable regardless of whether one was
provided by the page or not. This commit fixes this issue by making an
unavailable TOC only if one is not provided by the web page, otherwise
the TOC will be available.