v2.0.0

🚀 Features:

• Billingo class to unify all API endpoints (optional), plus a simple example
• Pydantic V2 support and code completion
• The former Swagger Generator has been replaced by the OpenAPI Generator.

⚠️ Breaking changes:

• Python 2.x support has been dropped.
• Generator change to OpenAPI Python generator, so models need to be reviewed.