Oh, of course the development is fun and exciting and a learning experience.
But before inviting others to use something, please think of how to make its use more clear. After all, I assume you post this so that people use it, not only admire your coding skills. There is a group of people who have learned to read and rely on man pages.
For example, the top-level README says:
> -s, --sort <CRITERIA>: Sort by "name", "size", or "date"
OK, does "date" refer to creation date, modification date, access date?
I can understand "size", but does it produce smallest-first or largest-first? It might not matter if... ah, no, there is no -r/--reverse flag.
Can I have more than one "criteria" (since the plural is used)?
Getting answers for such questions now means I have to go read the code in src/args.rs and follow to the implementation of the various functions. And in a few days, when I have the same questions again and I have forgotten the options, I will again have to dive into the code.
Please consider providing a short man page. It documents the "calling interface" to your program and makes it easier to use. I usually start writing one even before implementing the whole thing, to clearly articulate what I expect the program to do.
