Release 0.3-stefan (Seems to be production ready?)

Changelog:

1. Added settings (finally)
2. Added more properties for custom texts in Rich Presence
3. Added RPC Auto On/Off based on FlightGear data server availability
4. Added separate texts when Route Manager is set up
5. Fixed some bugs

This is my first serious repo and I am proudly announcing that this version seems to be production ready.
I have some plans for this project because it should be FGCompanion not FG-RPC. You can find one of future features in settings
And from now on, please use GitHub Issues for any issues
Finally, More aircraft icons coming very soon