This commit introduces the following changes to the Linux release process:
- **AppImage Support:** The GitHub Actions workflow (`flutter-ci.yaml`) now builds an AppImage alongside the existing .deb package for Linux releases. This involves:
- Installing `appimagetool` and `locate` as part of the build dependencies.
- Updating the `fastforge package` command to include `appimage` as a target.
- Adding a new AppImage configuration file (`linux/packaging/appimage/make_config.yaml`), based on the existing .deb configuration. A TODO has been added to this file to prompt review for AppImage-specific fields.
- **Generic Artifact Naming:** Both the .deb and AppImage files are now renamed to generic, version-less names (`fast-forge-linux-amd64.deb` and `fast-forge-linux-amd64.AppImage`) before being uploaded as release artifacts. This makes it easier to provide stable download links.
- **README Update:** The `README.md` has been updated with direct download links to these generically named .deb and AppImage files from the latest GitHub release.
