Support dto bundles

[HadiSDev]

It would be very nice if you could add support for saving the interfaces in a dtos.ts file, so we do not have to export every single file from our module. So something like bundle=true, would make all the C# classes in dir: workDir/Folder1/dtoClass1.cs into
ConvertDir/Folder1/Folder1DTOs.ts or ConvertDir/Folder1DTOs.ts, where Folder1DTOs.ts contains all of the interfaces for the C# classes under Folder1.

then in index.ts I can just do export * from "ConvertDir/Folder1/Folder1DTOs.ts";

I hope it makes sense :D