feat: TypeProvider for command line understandable by Fishshell

[dzmitry-lahoda]

Fishshell does next:

Man Page Completions
Man Page Completions Thumbnail Other shells support programmable completions, but only fish generates them automatically by `parsing` your installed man pages.

Let parse these in F# and createTypeProvider which allow to call many native Unix tools more easily by providing more strongly typed API. So F# will be chosen as scripting tool by more Unix users.

Flip this, given some tool with man page, let generate handler for its options. Allows reimplement tools in F# which satisfy same contract. Or start implementing F# tool with man page as declaration of command line args(see how Spec Flow+Cucumber works), and then move to AOT compiled language when needed.

Not sure that some standard exists to declare command line arguments (like it exists for some remote calls technologies), but 2 implementations going same route may end up in some standard (essentially calling process via command line is in many cases is like remote procedure call).