add target directory parameter

[brandedoutcast]

No description provided.

[AraHaan]

I personally would like this very much where for example, I might want to use this for say install a package to $DOTNET_ROOT/packs/ or $DOTNET_ROOT/shared/ for 3rd party .NET workload installers.

Also bonus points: if it will automatically download the absolute latest version of the packages they want and gives them the version similar to how one can install templates without providing the version parameter.

For this these lines would need to change: https://github.com/brandedoutcast/dotnet-grab/blob/master/NugetProvider.cs#L48-L49

Where L49 would have to be nested in an if (Directory.Exists(ExtractionPath)) and the path they need would have to be set as well.