Basic file sharing application with peers either providing or locating
and getting files by name.
While obviously showcasing how to build a basic file sharing
application, the actual goal of this example is **to show how to
integrate rust-libp2p into a larger application**.
Architectural properties
- Clean clonable async/await interface ([`Client`]) to interact with the
network layer.
- Single task driving the network layer, no locks required.
