Adds NAN service discovery, data path (NDP) establishment and a TCP
round trip over the Wi-Fi Aware network. W1 only probed the local
stack; these prove Wi-Fi Aware carries traffic between two devices.

Confirmed P10 (1.6.0TF) <-> P30 (1.6.0TA): SERVICE DISCOVERED,
NDP AVAILABLE, NAN ROUND TRIP OK.

Note: the responder must request the network before the initiator,
otherwise the data path does not come up.

Also moves README.md back to the project root.