Support AppImages

[saulrh]

.AppImage isn't a recognized extension, so even though this would absolutely run on my machine, it's not a candidate. AppImages, being single executable files that contain an entire program, seem like exactly what this project wants to support. For an example of a project that releases only AppImages, see https://github.com/hzeller/timg/releases/tag/v1.6.1.

This might require an additional flag for choosing a new name for the executable being downloaded - I'd want this to land on my disk as timg, not timg-1.6.1-x86_64.AppImage.

[autarch]

Yes, adding the extension would be easy. I think maybe we would need a --rename-exe arg to support renames. This could work for any sort of executable, though.

[saulrh]

Having a general-purpose --rename-exe arg would certainly be useful for other formats, agreed. "I want eza to land in my bin dir as ls", "I want to deconflict different versions of the same app", etc.

Should I split that out into a separate issue?

[autarch]

Hmm, now I'm remembering how ubi's behavior is kind of weird, where it actually already renames the executable in some cases. But this --rename-exe feature is still useful.

[autarch]

Support for AppImages and the --rename-exe-to flag are both in v0.4.1.