File format specification

[mipastgt]

This is just a hint and not a bug report but maybe it is helpful to have a look at this more up-to-date format specification provided by naviter instead of using the ancient one from over 25 years ago. (The link http://www.winpilot.com/UsersGuide/UserAirspace.asp is dead anyway.)
https://github.com/naviter/seeyou_file_formats/blob/main/OpenAir_File_Format_Support.md

[Turbo87]

yep, that is what I've been working with for the most part :)

I guess we should mention that somewhere in the README to make it more discoverable 😅