Issue #5229 - WebSocket documentation.

Updates after review.

Signed-off-by: Simone Bordet <simone.bordet@gmail.com>

documentation/jetty-documentation/src/main/asciidoc/programming-guide/server/websocket/server-websocket-standard.adoc

@@ -64,7 +64,7 @@ The `javax.websocket-api` artifact and the `websocket-javax-server` artifact (an
 To configure correctly your WebSocket application based on the standard `javax.websocket` APIs, you need two steps:
 
 . Make sure that Jetty xref:pg-server-websocket-standard-container[sets up] an instance of `javax.websocket.server.ServerContainer`.
-. Use the `ServerContainer` APIs in your applications to xref:pg-server-websocket-standard-endpoints[register your WebSocket endpoints] that implement your application logic.
+. xref:pg-server-websocket-standard-endpoints[Configure] the WebSocket endpoints that implement your application logic, either by annotating their classes with the standard `javax.websocket` annotations, or by using the `ServerContainer` APIs to register them in your code.
 
 [[pg-server-websocket-standard-container]]
 ===== Setting Up `ServerContainer`

documentation/jetty-documentation/src/main/asciidoc/programming-guide/server/websocket/server-websocket.adoc

@@ -29,7 +29,6 @@ The standard APIs provide few features that are not present in the Jetty WebSock
 
 On the other hand, the Jetty WebSocket APIs are more efficient and offer greater and more fine-grained control, and provide features that are not present in the standard APIs:
 
-* `MessageSink` for advanced, asynchronous, message streaming with backpressure.
 * Suspend/resume to control backpressure.
 * Remote socket address (IP address and port) information.
 * WebSocket upgrade handling via Filter or Servlet.