BlueBird 757-200 Physics & Flight Model Improvement

This add-on enhances the physics and flight model of the BlueBird Simulations Boeing 757-200, aiming to deliver more realistic handling and performance. It improves pitch, roll, and yaw response while reducing excessive control sensitivity and better simulating aircraft mass and inertia. The update also introduces an initial correction for climb rate discrepancies in Pratt & Whitney engine variants, maintaining autopilot compatibility. All changes are fully reversible and require the original BlueBird 757-200 to be installed.