Enhance documentation site to have versions

[timsaucer]

Is your feature request related to a problem or challenge?

In other projects, when you go to the API documentation, you can select a specific version. As our user base is growing and there are breaking changes between versions, it would be nice to have an option for users to select a documentation version. For example, as we are about to merge in DF44 if someone reviews the online documentation for Execution Plan but they are working with DF 43 it will cause confusion since the plan properties have changed.

Describe the solution you'd like

I'm not sure what the best tools are for building documentation sites, so this will require a bit of research.

Describe alternatives you've considered

We could leave as is and just always recommend going to the latest version, but that will become less and less a viable option for all users as adoption increases.

Additional context

No response