Replace custom rem hugo shortcode template with HTML comment. HTML comments are now
allowed in Hugo without enabling unsafe HTML parsing.
Improve the text in the comment: Remove unnecessary quoting, and avoid impression that
make backenddocs has to be run and results committed, since we have a lint check which
will then report error because we want to prevent manual changes in autogenerated sections.
Disable the markdownlint rule line-length on the autogenerated marker line.
Make the autogenerated marker detection a bit more robust.
See #8942 for more details.
The config question "Use auto config?" confused many users and lead to
recurring forum posts from users that were unaware that they were using
a remote or headless machine.
This commit makes the question and possible options more descriptive
and precise.
This commit also adds references to the guide on remote setup in the
documentation of backends using oauth as primary authentication.
