Printipy

Dependency updates:

- requests to 2.32.2
- dataclasses-json to 0.6.6

Linter and formatter updates:

- dropped black and flake for ruff
- ran reformat and checker

- ShippingCost `express` is now optional - fixes 20
- Incrementing Jinja2 to 3.1.3

- Updating angle from float to int

Fully settled on the Python organization and layout.

Documentation included!

Tests passing with Python 3.9+

- Publish now has default values for everything
- Added `channel` to ProductExternal