Q: How to use this crate in programming contests?

For instance, how to submit my solution that uses this crate to a codeforces judge?
They require your solution to be in one file. Is there any kind of pre-submission script that could handle dumping the entire crate in the solution file?

This would be a really nice addition, if someone wants to add it. So far, I've just manually copied the modules I needed on a per-problem basis.