2.0.0

Major release with non-back-compatible changes.

Tentatively included:

• Rename the top-level package from "logger", probably to "logging".

Dependent on stuff in the linked slf4m-jankalog "SLF4M 2.0.0" milestone.

The 2022-12-01 due date is just a placeholder to get our milestones to sort correctly. That's not a real due date or delivery estimate.