[IMRF-97] Feature request: Support running `importify` on stack-script projects

[vrom911]

It would be nice also to be able to run importify on single-file projects.
I tried it on this project and I received

[importify:WARNING] importify was executed outside of project

which is reasonable for current ability of the tool.

[chshersh]

Thanks for your feedback, @vrom911! I agree, it would be really great to run importify over single files or even stack-script projects. This is known issue, so I'll rename the title, don't worry about that.

Importify doesn't work on such files because importify requires .cabal file for caching. With scripts things are more difficult because we want to extract dependencies for script somehow from comment.