minor textual changes to README and dedicated example

[fantapop]

Including:

• sync variables mentioned in README with actual example
• add example values for allow list name and CIDR IP
• remove limited access denotion for Azure clusters
• add link to terraform sensitive values recommendations in example comment.

Commit checklist

• [x] Changelog
• [x] Doc gen (make generate)
• [ ] Integration test(s)
• [ ] Acceptance test(s)
• [ ] Example(s)