Adding example server setup page  (rebased onto develop)



This is the same as gh-804 but rebased onto develop.

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See https://trello.com/c/MLBX0xMP/156-server-set-up-and-traffic
This is the first work to add an example server set-up page to help sysadmins work out what set-up they require depending on their expected user traffic etc.
Ideally, we would add info on nightshade before publishing this, and I'm not sure how helpful it is without performance stats…
Plus some very minor tidying to make the capitalisation of all the sysadmin headings match.