0.0.96 RC, with typo fixed

Update Flatpak local manifest

CI: further fine tune GH Release creation

Do not add AppImage at GitHub Releases

To avoid complaints that it doesn't work. (Cloudsmith snapshots are
still there, even though nobody seems to use them).

AppData: fix a typo

Actually, use that screenshot Linux-wide

...because Flatpak ultimately takes the screenshot data from
the AppStream file, which is also mainly a Linux thing (so far).

0.0.95, with adjusted AppStream file

The previous one did not pass appstream-util validation.