Our multiversion testing support is very complicated. We have lots of concepts like last_lts vs last_continuous, old vs new, multiversion tags, version_combinations, etc. It can be difficult to know what all this means as how to understand what is going on with multiversion tests. We should document how multiversion testing works, what the multiverison terminology means, and how engineers are expected to interact with multiversion testing.

As a database contributor,
I want to documentation for multiversion testing,
So that I can understand how it works.

AC:

• A page exists here describing multiversion testing.
• The documentation should include:
  • Definitions of multiversion terminology.
  • An overview of how multiversion testing works.
  • Anything engineers should know when working with multiversion tests.