In docs we have a bunch of places that mention e.g. "standalone.localdomain" as the example host. While not incorrect and we always mention that users should fill in their values, it would be better to use examples more relevant for the product, e.g. "example-controller-0.localdomain".

Acceptance criteria:

• Docs examples in the OpenStack adoption procedure are focused around 3-controller use case rather than standalone deployment.
• The names of the servers must be obvious that are examples for customers, e.g. "example-controller-0.localdomain".
• We keep coherence of docs at least at the level where it was before this Epic. This should mainly mean using a stable set of IP addresses and hostnames in our examples. E.g. we don't want "example-controller-0" in one section and "controller-example-0" in another section.