Issue

There is no documentation about how to perform minor upgrades and rollbacks on PostgreSQL 16.

Solution

• Update "Upgrades" landing page with some context around refresh
• Create new "How to perform a minor upgrade" guide
• Create new "How to perform a minor rollback" guide
• Create a "Glossary" page for all docs, which for now only contains some simplified refresh terminology for users
• Update releases page

I tried to make it easy to skim through, but still emphasizing critical points. I avoided large blocks of text in favor of referencing other documentation and resources.

It does not cover every single nuance, but my intention is to merge a first iteration of refresh documentation as soon as possible so that users have something to part from. I expect it to grow and evolve in future PRs.

Checklist

• I have added or updated any relevant documentation.
• I have cleaned any remaining cloud resources from my accounts.

DPE-7949