[Cin] Creating AppImage

[Andrea paz]

Yes, appimage uses squashfs and then compresses it with gzip or
something else. This is done, for example, with the command:

appimagetool --comp .../squashfs-root /tmp/my-appimage.appimage

(see: https://github.com/AppImage/AppImageKit)

But appimagetool is not available for all distros; for example I
couldn't find it for Fedora. Also linuxdeploy is used to
create/compress an appimage, but reading the manual I don't really
understand how to do it...