Polario

Add py.typed to hint we contain types in here.

Add a tiny CLI, called `polario` which allows you to inspect a parquet file.

What's Changed
* Add Enum for existing data bahavor in https://github.com/bneijt/polario/pull/11
* Add update support in https://github.com/bneijt/polario/pull/7
* Add append method in https://github.com/bneijt/polario/pull/13


**Full Changelog**: https://github.com/bneijt/polario/compare/0.1.0...0.2.0

This is the basic functionality: read and write a Hive dataset with parquet files.