[Replicant] Website updates for Replicant 6.0 release

[Wolfgang Wiedmeyer]

The patches in this patch series get the website ready for a release
of Replicant 6.0. Three patches that update the devices section and
add Replicant 6.0 screenshots are not included as they mostly include
images. They can be found on my Replicant 6.0 branch, together with
the other patches[1]. I added a patch that makes it possible to host
the website in a subfolder. This patch was helpful for my personal use
and is not important.

A version of the website with all the patches can be browsed on my
webspace[2].

I submitted two other patches, one about the CAcert certificate and
another one updating the general advice section. These can already be
applied before the Replicant 6.0 release. Denis submitted some more
patches a year ago that update the "Freedom and privacy/security
issues" tab. These are still mostly not merged.

Best regards,
Wolfgang


[1]  https://code.fossencdi.org/replicant_website.git/log/?h=replicant-6.0

[2]  https://fossencdi.org/replicant/website/