• add __reversed__()
• add efficient __contains__()
• improve CLI startup time (replace pkg_resources => importlib)
• tqdm.autonotebook warning & std fallback on missing ipywidgets (#1218 <- #1082, #1217)
• warn on positional CLI arguments
• misc build/test framework updates
  • enable py3.10 tests
  • add conda dependencies
  • update pre-commit hooks
  • fix pytest config (nbval, asyncio)
  • fix dependencies & tests
  • fix site deployment