We provide more precise instructions and troubleshooting when restart
for the first time, independently of whether it's a temporary Tails (for
Windows, Linux, and Mac) or a final Tails (for Debian).

- Add usual CSS tricks to expert.css
- Don't display steps and states for expert.
  This make the layout of command line instructions much easier, and
  experts don't need them anyway :)
- Prepare the work for the Debian scenario.

For the first testing sessions it won't be in Debian backports.

This scenario will be advertised as "using the command line and GnuPG"
which should filter out people quite a bit. So people actually opening
this page could be interested in learning how to do this.

This puts all the GnuPG bureaucracy first (and might turn people down
before they actually spend the time to download the ISO).

1. An [[!inline directive cannot be turned into a <pre> through markdown
indentation, nor can it be inserted inside a <pre>. Plus either <pre> or
white-space indentations properties insert an extra new line on top of
the section.

2. ikiwiki interprets <tails@boum.org> as an email address so we have to
escape < and >.

We'll generate this at release time. This will remove all possible
ambiguity on the date, possible replay attacks, very quick emergency
releases, etc.