webrtc/: Add libp2p WebRTC browser-to-server spec (#412)

Enable browsers to connect to public server nodes without those server nodes
providing a TLS certificate within the browser's trustchain.

Co-authored-by: Chinmay Kousik <chinmaykousik1@gmail.com>
Co-authored-by:  Anton Kaliaev
Co-authored-by: Thomas Eizinger <thomas@eizinger.io>
Co-authored-by: Marten Seemann <martenseemann@gmail.com>

README.md

@@ -89,6 +89,7 @@ The protocols described below all use [protocol buffers](https://developers.goog
   peer discovery
 - [secio][spec_secio] - SECIO, a transport security protocol for libp2p
 - [tls][spec_tls] - The libp2p TLS Handshake (TLS 1.3+)
+- [webrtc][spec_webrtc] - The libp2p WebRTC transport
 - [WebTransport][spec_webtransport] - Using WebTransport in libp2p
 
 
@@ -128,4 +129,5 @@ you feel an issue isn't the appropriate place for your topic, please join our
 [spec_mdns]: ./discovery/mdns.md
 [spec_autonat]: ./autonat/README.md
 [spec_dcutr]: ./relay/DCUtR.md
+[spec_webrtc]: ./webrtc/README.md
 [spec_webtransport]: ./webtransport/README.md

connections/hole-punching.md

@@ -166,5 +166,5 @@ connections across the various permutations of the two dimensions.
 [ipfs-kademlia]: https://docs.ipfs.io/concepts/dht/
 [Kademlia]: https://github.com/libp2p/specs/blob/master/kad-dht/README.md
 [Gossipsub]: ../pubsub/gossipsub/README.md
-[WebRTC]: https://github.com/libp2p/specs/issues/220
+[WebRTC]: ../webrtc/README.md
 [WebTransport]: https://github.com/libp2p/specs/pull/404