cf. team#41991

Still incomplete, not hooked into anything... I have had this in my
local tree for months at this point, and it seems better to commit it
that to leave it lying around like this.

We stop short of rewriting all playbooks for Prometheus, and instead
add references to the task of adding playbooks for
everything (prometheus-alerts#16) where we found references to
nagios.

It took me a while to reach that today.

I kept having trouble finding links to the right thing. Hopefully this
will clarify things.

I forgot to change it after the copy/paste

Mostly consistency in capitalization, adding some links to related
issues, spell-checking and splitting long sentences.

See: team#41948

They don't seem to like GitLab links to wiki pages. :-(

See: https://gitlab.torproject.org/tpo/tpa/wiki-replica/-/jobs/820082

Prevent this error:

    (stdin): Kramdown Warning: No link definition for link ID 'toc' found on line 7

See: https://gitlab.torproject.org/tpo/tpa/wiki-replica/-/jobs/820071

refs team#41948

refs team#41948

refs team#41948

refs tpo/tpa/tails/sysadmin#18166

At least one user was confused and put submission.torproject.org, and
used torproject.org as the server name.

I was trying to show how much disk space Prometheus was using and
couldn't find good answers.

donate: rewrite activity diagram to clarify the perk data workflow

See merge request !66

It wasn't clear to me exactly what was going on with those
notes. Ideally, we'd also find a way to automate that synchronization
process (as mentioned above), so it feels better to make an actual
arrow there, even though it doesn't fully reflect the way this
actually works underneath.

I also feel it looks *much* better to move the CiviCRM column to the
left.

See: tpo/web/donate-neo#79

/assign_reviewer @stephen