The rationale here is that Ganeti has its own inventory and capacity
evaluation system, so we do not *need* the Spreadsheet for that
purpose. We still do need the spreadsheet for cost tracking however,
so keep the documentation procedure for machines that "are not in
Ganeti", basically.

This is:

    ikiwiki2hugo.py --exclude .pytest_cache

With the latest script from:

<https://gitlab.com/anarcat/scripts/-/blob/master/ikiwiki2hugo.py>

... as of right now.

The latter is actually one of two standard file extensions (as per
RFC7763, the other being .markdown). It's also the extension expected
by GitHub, GitLab, and other wiki software.

So for the sake of future-proofing and compatibility, rename all files
to the new name.

This will hopefully not break anything: the file extension is not
present in the rendered version anyways.

Those are more future proof and will work in gitlab.

When weasel told me about this, he did say it was optional. And in
practice, nevii is fast enough: it runs `ud-replicate` every 5 minutes
(like everyone else) and so syncs DNS changes with the LDAP server
fast enough so that we don't need ot bother with this.

The grml-debootstrap install process properly sets up sources.list
with security upgrades, and we should expect the same of any install
process.

tsa-misc is not exactly a pre-requisite: none of the installers
currently deploy it, and it might eventually go away if we go the
"remote bootstrap" way.

tmpfs and swap are correctly setup on ganeti and hetzner cloud, so we
don't need them in the common trunk.

This is mostly so that we know how to design the previous installers.

The rationale here is we remove one more step in the installer:
instead of going back and forth between the master and client, we run
one command on both, simultaneously, and only transfer the SHA256
checksum between the two.

This could eventually be automated in such a way that we can do this
unattended if we have SSH access on both machines.