Custom Flight GUI: Sideslip Indicator

[86thFG_theRedPanda]

Something that would be really useful and help players would be some sort of sideslip indicator in the custom flight GUI.

For new players it would make learning to coordinate turns much easier, especially in propeller aircraft. 

Another reason to add this as a feature is that a pilot would be able to feel this naturally and correct it without having to look down to check it. This would help compensate for the missing feedback a bit like camera shake or buffeting sounds for stalls.