Linux: AppImage packaging

[shuvashish76]

Request to add AppImage package available for linux users.

Unlike other packages AppImage is a community project & you could install without the need for a centralized store.
The use-case is same as Windows portable version.
Comparison : https://github.com/AppImage/AppImageKit/wiki/Similar-projects

AppImage having update information would also recognized by other software e.g. AppImageLauncher , AppImageUpdate, AppManager, AM etc...

info:

• https://github.com/AppImageCommunity/AppImageUpdate#update-information-overview
• https://github.com/AppImage/AppImageSpec/blob/master/draft.md#update-information
• https://github.com/ivan-hc/AppImage-tips

Lots of projects already support updating AppImage e.g: LibreWolf, KeePassXC, Sigil etc.