What's Changed
* EventRouter -> EventRegistry
* PlaceholderRouter -> PlaceholderRegistry
* aiogram_broadcaster.storage -> aiogram_broadcaster.storages
* Reworked placeholder system
* Improved type annotations
* Contents allows pydantic extra kwargs
* Contents has an unregister method
* Improved KeyBasedContent
* The “include()” method of EventRegistry, PlaceholderRegistry now is “bind()”
* File architecture changes
**Full Changelog**: https://github.com/loRes228/aiogram_broadcaster/compare/v0.4.6...v0.4.7