feature: AppImage

[BlakeBarrett]

Ask

As a Linux user, I would like to be able to install via AppImage, so that I can drag/drop install on Linux, just like a mac.

Notes:

Read up about it here then add it to the GitHub action for producing release artifacts:

• https://odilondamasceno.medium.com/creating-appimage-with-flutter-d19ef8b53158
• https://github.com/AppImageCrafters/appimage-builder-flutter-example?tab=readme-ov-file
• https://appimage-builder.readthedocs.io/en/latest/examples/flutter.html

[BlakeBarrett]

Here's a project to create an AppImage from Flutter's Linux build output. https://github.com/AppImageCrafters/appimage-builder-flutter-example Let's add that to a workflow.