Feat: AppImage Release for Linux

### Describe the feature

Providing an AppImage release would allow PictoPy to run on most modern Linux distributions without requiring conversion tools (e.g. debtap) or manual extraction

### Add ScreenShots

Need Appimage

### Record

- [x] I agree to follow this project's Code of Conduct
- [x] I want to work on this issue

### Checklist before Submitting.

- [x] Have you updated docs for it?.
- [x] Have you added unit tests?.
- [x] Have you made sure unit tests pass?
- [x] Have you made sure code formatting is correct?
- [x] Does it contain any style related issues?