Short Description:
Add terminateAtApogee parameter

Long Description:
If you want to make the simulation stop at apogee, you can use the terminateOnApogee parameter on the flight object. But what about when you want to stop the simulation at the moment the rocket leaves the rail? Add a similar parameter!

Currently, for RocketPy, the rocket is considered to be out of rail at the moment the uppermost rail button leaves the rail.

Useful links:
Try to find terminateAtApogee at the code