Add another airframe to QGC

How do I add a new airframe in QGC?

Like here:

@LorenzMeier, @DonLakeFlyer

Gents, I have written up the files for another flying wing, this one is UAV Mapper by Tuffwing. I do not know how to upload it to github, so it appears in the airframe section. Are you able to help me getting this airframe added to QGC. I have attached the airframe and mixer parameters documents.UAV Mapper Mixer.pdf (138.8 KB) UAV Mapper.pdf (142.8 KB)