Remove Remoting and EJB sections in reference docs

Author: rstoyanchev

src/docs/asciidoc/index.adoc

@@ -14,8 +14,7 @@ JDBC, R2DBC, O/R Mapping, XML Marshalling.
 STOMP Messaging.
 <<web-reactive.adoc#spring-webflux, Web Reactive>> :: Spring WebFlux, WebClient,
 WebSocket, RSocket.
-<<integration.adoc#spring-integration, Integration>> :: Remoting, JMS, JCA, JMX,
-Email, Tasks, Scheduling, Caching.
+<<integration.adoc#spring-integration, Integration>> :: JMS, JCA, JMX, Email, Tasks, Scheduling, Caching.
 <<languages.adoc#languages, Languages>> :: Kotlin, Groovy, Dynamic Languages.
 <<appendix.adoc#appendix, Appendix>> :: Spring properties.
 https://github.com/spring-projects/spring-framework/wiki[*Wiki*] :: What's New, Upgrade Notes, Supported Versions,