Poniard 0.3.0

What's Changed

• Migrate to nbdev by @rxavier in #29 & #30
• New documentation at https://rxavier.github.io/poniard/
• Better handling of removed and added estimators (no longer readded if pipelines are rebuilt)
• Fix reassign_types for non-modified types.
• Fix for wandb config logging
• TargetEncoder now handles non-numeric and non-boolean classification targets.

Full Changelog: 0.2.4...0.3.0