Add basic administration information to "Fundamentals Page"

As we add many more features and more services to our product, keeping track of quite what applies to what version and what has changed in a new version is difficult to see at a glance for our customers.

At a risk of duplicating some information and the issues that can bring, it would be great to include the most important pieces of information that administrators of a Couchbase Server cluster may need, like network port requirements, to the Intro/Fundamentals page for each version of the service.