added files to create AppImage

[efa]

this should fix #688 (comment)

Note: I used a work around in AppImage creation, manually including the two files listed at:
#707 (comment)
this increase a lot the creation time, sorry.

The generated AppImage should work on any distro newer than the one the binary and AppImage is created on (or with glibc newer that the build host). As now I tryed:
gImageReader_3.4.2_2025-03-07_Linux_x86_64_64bit.AppImage 47 MB
on Debian12 only, but it is an AppImage rule

[manisandro]

Thanks! Would it be possible to also add a workflow to build the appimage automatically as a CI job?

[efa]

are you speaking about "GitHub Actions: build and test multi-platform", or another external service?

[manisandro]

Yes Github Actions - a workflow similar to [1].

[1] https://github.com/manisandro/gImageReader/blob/master/.github/workflows/build.yml

[efa]

I have no experience with Github actions, but it's something that I have in my todo list also for my applications.
I'd say it's the right time to study how it works and try it