Update doc for WebTransport.

QuicTransport and Http3Transport are merged to a single WebTransport
interface.

Author: jianjunz

doc/Client-Portal Protocol.md

@@ -620,4 +620,4 @@ Step 2: Receive a response from server.
 }
 ```
 
-Step 3: Create a new QuicTransport or get an existing QuicTransport, then create a new BidirectionalStream or SendStream. Write data to stream. The URL of QuicTransport should be included in token. QuicTransport is shared by all media streams, data streams and signaling which belong to the same client.
+Step 3: Create a new WebTransport or get an existing WebTransport, then create a new BidirectionalStream or SendStream. Write data to stream. The URL of WebTransport should be included in token. WebTransport is shared by all media streams, data streams and signaling which belong to the same client.

doc/proposals/quic-transport-payload-format.md renamed to doc/design/quic-transport-payload-format.md

@@ -1,6 +1,6 @@
 # QUIC Transport Payload and Message Format
 
-This post defines the payload and message format for data transmitted over [QuicTransport](https://wicg.github.io/web-transport/#quic-transport).
+This post defines the payload and message format for data transmitted over [WebTransport](https://w3c.github.io/webtransport/#web-transport).
 
 ## Streams
 
@@ -28,10 +28,10 @@ It may increase about 2% network cost.
 
 ## Authentication
 
-After creating a QuicTransport, a stream with session 0 should be created for authentication. If signaling is transmitted over QuicTransport, authentication follows the regular process defined by [Client-Portal Protocol](https://github.com/open-webrtc-toolkit/owt-server/blob/master/doc/Client-Portal%20Protocol.md). Otherwise, client sends a following message with UTF-8 encoding in JSON format to server.
+After creating a WebTransport, a stream with session 0 should be created for authentication. If signaling is transmitted over WebTransport, authentication follows the regular process defined by [Client-Portal Protocol](https://github.com/open-webrtc-toolkit/owt-server/blob/master/doc/Client-Portal%20Protocol.md). Otherwise, client sends a following message with UTF-8 encoding in JSON format to server.
 
 ```webidl
-interface QuicTransportLoginInfo {
+interface WebTransportLoginInfo {
   attribute DOMString? token;  // Base64 encoded token.
 };
 ```