Dirs is intentionally tainted by MPL-2.0

Hello, I wanted to raise a note that this crate currently has a transitive dependency on option-ext. That library is MPL-2, a copyleft license. The option-ext dependency is brought in via dirs. The maintainer of dirs has explicitly stated that they added a dependency on option-ext for the express purpose of tainting the use of dirs with MPL-2, which thus taints any use of shellexpand. I recommend switching to an alternate dependency such as etcetera, which does not suffer from this tainting issue.