What's Changed
* Add BADA4 wrapper as an add-on
* Refactor trajectory generation module
* New temperature approximation for `casadi/aero_override.py`
* Fix missing attribute `use_synonym` in `FuelFlow` init by nhuet in https://github.com/junzis/openap/pull/50
* Adding temperature shift to atmosphere model by dus42 in https://github.com/junzis/openap/pull/54
**Full Changelog**: https://github.com/junzis/openap/compare/v2.0...v2.1