Chunk info and simplify language in the Pulpcore Concepts and Terminology docs
As I was reading through this section https://docs.pulpproject.org/pulpcore/concepts.html - a few things occurred to me.
- It's painful to have to jump to the glossary to get initial definitions
- It would be nice if there were sub headings to orient the reader
- Some of the language is very developer-focused rather than user focused.