feat: attach path to `fs::read_dir` errors

[nathanregner]

My use case is probably a bit niche, but I store most of my git repos in a separate case-sensitive APFS volume on my Mac. There are a number of directories created by the system that are unreadable by my user (like .fseventsd). I can work around it by adding entries to excluded_dirs, but this makes it easier to tell what's going on :smile:

Error: IO Error
├╴at src/repos.rs:88:18
├╴Could not read directory "/Volumes/dev/.fseventsd"
│
╰─▶ Permission denied (os error 13)
    ╰╴at src/repos.rs:88:18

[jrmoulton]

Looks great. Thanks!