C# can't really use Inproc transport as indicated by "language stacks" blogpost

[jtattermusch]

https://grpc.io/blog/grpc-stacks mentions "For example, you could use C# instead, and use an In-Process transport", which doesn't seem to be accurate. While this is true in principle, C# actually doesn't expose the APIs to create in-proc channel (such as https://github.com/grpc/grpc/blob/618a3f561d4a93f263cca23abad086ed8f4d5e86/src/core/ext/transport/inproc/inproc_transport.h#L26), and therefore you can't currently use an inproc transport with C#.
We should update the blogpost and provide a better example.

This has been pointed out by https://groups.google.com/forum/#!msg/grpc-io/-H_Zjletyng/Q8xuwFluAgAJ.