How to determine app name?

```$APPNAME.png```, ```$APPNAME.desktop``` are going to be different for each app. How can a tool know where to look?

I suppose you can check for any *.png or *.desktop in the root folder, but that seems like it could cause issues if there are multiples of any of these. Perhaps there needs to be something like "MUST include only ONE .desktop file in the root directory" and use the name of the .desktop to get the .png.

Alternatively, you could require that there be an ELF section called ```.appimage_name``` and maybe even ```.appstream_id``` for the AppStream stuff. To get even more specific, you could have ELF sections for ```.icon_path```, ```.desktop_path```, and ```.appstream_path```. This may be overusing the ELF sections though, and it might make sense to just put it in a file somewhere.

I know that ideally the AppImage file name would include it, but this is not always guaranteed. For instance, a user makes a copy of an AppImage and the new name is ```Copy of $APPNAME-$VERSION-$ARCH.AppImage```. Without proper checks, this would resolve to ```Copy of $APPNAME.desktop```.