feat: Create a Nushell script for 'files' module

[gmpinder]

So from testing out errors, I've found that putting bool checks into a variable makes it so that we can take the span of the bool variable so that when we run into an error, we can supply that span to the error. This makes it easier for users to see how the check is happening.

Example of one of the error messages:

[xynydev]

Nice! Are we planning to write all modules in Nushell going forward? Should probably discuss.

If and since the files@v1 and files@v2 introduced in this PR use the exact same syntax and support the same featureset, what is the reason for keeping the bash version around?

[gmpinder]

Nice! Are we planning to write all modules in Nushell going forward? Should probably discuss.

If and since the files@v1 and files@v2 introduced in this PR use the exact same syntax and support the same featureset, what is the reason for keeping the bash version around?

I figured I'd version it mostly cause I wanted to drop the old schema in favor of only the source and destination schema.

[xynydev]

I figured I'd version it mostly cause I wanted to drop the old schema in favor of only the source and destination schema.

Oh yeah, I didn't notice that. Sounds good. That means we have to announce this change, so we better bundle it with #336. Also, versioned modules need separate README's for each version. Feel free to look at what's happening with the default-flatpaks PR.