Describe Namespace and Community catalog

Fabio Pitino - PTO until Jan 1requested to merge
ci-catalog-clarify-feature-availability into master

What does this MR do and why?

Related to the discussion here: &9957 (comment 1323484246)

Describe Namespace and Community catalog

Introduce Namespace Catalog as a paying feature and Community Catalog as a free feature. Describe the differences between those and how they can work together on the same instance.

MR acceptance checklist

This checklist encourages us to confirm any changes have been analyzed to reduce risks in quality, performance, reliability, security, and maintainability.

Merge request reports