Use code includes and tabs in WebSocket documentation

See gh-22171

framework-docs/modules/ROOT/pages/web/websocket/fallback.adoc

@@ -82,49 +82,9 @@ https://sockjs.github.io/sockjs-protocol/sockjs-protocol-0.3.3.html[narrated tes
 [[websocket-fallback-sockjs-enable]]
 == Enabling SockJS
 
-You can enable SockJS through Java configuration, as the following example shows:
+You can enable SockJS through configuration, as the following example shows:
 
-[source,java,indent=0,subs="verbatim,quotes"]
-----
-	@Configuration
-	@EnableWebSocket
-	public class WebSocketConfig implements WebSocketConfigurer {
-
-		@Override
-		public void registerWebSocketHandlers(WebSocketHandlerRegistry registry) {
-			registry.addHandler(myHandler(), "/myHandler").withSockJS();
-		}
-
-		@Bean
-		public WebSocketHandler myHandler() {
-			return new MyHandler();
-		}
-
-	}
-----
-
-The following example shows the XML configuration equivalent of the preceding example:
-
-[source,xml,indent=0,subs="verbatim,quotes,attributes"]
-----
-	<beans xmlns="http://www.springframework.org/schema/beans"
-		xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
-		xmlns:websocket="http://www.springframework.org/schema/websocket"
-		xsi:schemaLocation="
-			http://www.springframework.org/schema/beans
-			https://www.springframework.org/schema/beans/spring-beans.xsd
-			http://www.springframework.org/schema/websocket
-			https://www.springframework.org/schema/websocket/spring-websocket.xsd">
-
-		<websocket:handlers>
-			<websocket:mapping path="/myHandler" handler="myHandler"/>
-			<websocket:sockjs/>
-		</websocket:handlers>
-
-		<bean id="myHandler" class="org.springframework.samples.MyHandler"/>
-
-	</beans>
-----
+include-code::./WebSocketConfiguration[tag=snippet,indent=0]
 
 The preceding example is for use in Spring MVC applications and should be included in the
 configuration of a xref:web/webmvc/mvc-servlet.adoc[`DispatcherServlet`]. However, Spring's WebSocket