- Slightly refactored request flow
- Added `App.command_group` decorator
- Added additional arguments acceptance in `AppModule`
- Added static paths customisation for `AppModule`
- Added `workers` options to `serve` command
- Changed default logging level to `info` in `serve` command
- Changed default `SameSite` policy for session cookies to `Lax`
- Added official Python 3.9 support