Consider adding an --exclude argument for Windows-compatible globbing

Hi @RomanHotsiy and @adamaltman 👋🏼

I work on a project (I think you know the one!) that uses a command like this:

openapi bundle -o dist --ext=json definitions/*[!next].yml

We use that [!next] part to ignore files with next in their name. But this type globbing expression is not supported on Windows. At one point we discussed that this package, openapi-cli, could support an --exclude argument or similar that could be used to achieve this same effect while still supporting Windows users.

cc @jf205 @rachmari

[andriyl]

fixed on #196

[zeke]

Sweet! Thank you.