Updating TOML parsing for Python 3.11
Use tomllib if available, else use toml.
An upcoming release will drop support for toml and therefore become
supported on Python 3.11+ only.
Toolchain updates to accompany migration away from setup.py
Migrate away from setup.py
Ignore mypy complaint about toml stubs
Add license file; fix to makefile
Version 1.0.1; marked internal functions as private
Bug fix for multivariate options
Fix Makefile; pipx no longer supports --spec
Documentation; mypy integration into tests