Docs addition/improvement: caching examples

I think there are some examples and clarity we could bring to the cache control and response cache plugin docs that would help users understand how they work and how to implement them.

Opening this issue in response to #7416

Review the cache control and response cache plugin documentation, then use issue #7416 for the original context. Add clear examples showing how each works and how users can implement them; the documentation should make both features easier to understand.

Written by the indexing model from the issue text.