Begin documentation with a simple copy&paste example

https://github.com/ok2cqr/cqrlog/issues/110#issuecomment-416686307

> I'm sorry but I'm giving this up. After 12 hours of my daily work I'm trying to create just simple app image without any extra dependecies like mysql, libhamlib, xplanet etc. __I found documentation but it's tons of information but there is no simple step by step how to.__ I'm sorry, but I'm not interesting about any internal functions, not yet. I just wanted to create simple image from cqrlog.AppDir directory produced by make DESTDIR='cqrlog.AppDir' with a desktop file and icon. __No way without reading MB of documentation and manuals how it works internally.__ Maybe I'm too tired for this. I'm sorry.

We should have a simple copy&paste example as the first thing in the manual. All the details can follow thereafter for those who are really interested.

I feel with the author. He does not care about how AppImage works internally, he just wants to get an AppImage made as fast as possible without having to learn a lot about AppImage.