Add option for globby to include directories

[KasparEtter]

Thanks a lot for the --ignore-directories option! As it turned out, after upgrading globby from 6.1.0 to 11.0.0, directories are already ignored by default by globby since 7.0.0:

The nodir option is now also true by default. This means that by default it will now only return file paths, not directory paths.

I figured this out after discovering that the --ignore-directories option had no effect and then debugging your tool locally because I couldn't figure out how your commit would have changed that. It seems that the option nodir no longer exists (thanks to the TypeScript compiler in Visual Studio Code I already had an error before even trying 🎉) and onlyFiles is the right option to use.

Strictly speaking, your 6.1.0 release had thus a breaking change and should have been tagged 7.0.0. While this issue was quite subtle, it would be nice to have unit tests to catch regressions like this. But overall I really like this tool so I stop complaining! 🤭 🤓