fix: `--all` positional argument handling

[massivebird]

See #5. I hacked the solution together which technically resolves the issue, but it's super duper messy.

Basically this is the culprit and I want it dead

        // Trying to handle `--all` with a path argument, where the path is
        // stored in the `query` positional argument. Copy it over.
        let root = if matches.get_flag("all") && get_arg("query").is_some() {
            PathBuf::from(get_arg("query").unwrap())
        } else {
            get_arg("root").map_or(
                std::env::current_dir().wrap_err("Failed to retrieve current directory.")?,
                PathBuf::from,
            )
        };

[massivebird]

Maybe the solution is to double down. I can throw an eyre error if I manually detect two positional arguments with --all.