Geo setup guide steps are desynchronised and it's not obvious that they need to be followed in a particular order

Fresh off a customer call with @lbot for a failing Geo installation.

Ultimately the problem was that the Geo setup guide (http://docs.gitlab.com/ee/gitlab-geo/#using-omnibus-gitlab) hadn't been followed in order. Database replication had been skipped over. The customer had been following http://docs.gitlab.com/ee/gitlab-geo/configuration.html

It's not completely obvious from each of the step pages (1-7) that the page is just a step in the complete process. We should include a large banner to that effect at the top of each step page. There is a list of earlier and later steps, but it's very tame - and doesn't include all steps on all pages.

The current heading of each step page looks a bit like:

The warning is there but super-easy to skip over. Let's make it bigger, and let's make the step list in each step page accurate.

/cc @lbot