Merge pull request #27810 from akka/wip-more-deprecation-1-patriknw

Deprecate akka.Main

akka-actor/src/main/scala/akka/Main.scala

@@ -18,6 +18,7 @@ import scala.util.control.NonFatal
  * top level application supervisor actor. It will shutdown
  * the actor system when the top level actor is terminated.
  */
+@deprecated("Implement your own main class instead, from which you start the ActorSystem and actors.", "2.6.0")
 object Main {
 
   /**

akka-docs/src/main/paradox/additional/packaging.md

@@ -71,7 +71,7 @@ The plugin configuration might look like this:
       <transformer
        implementation="org.apache.maven.plugins.shade.resource.ManifestResourceTransformer">
        <manifestEntries>
-        <Main-Class>akka.Main</Main-Class>
+        <Main-Class>myapp.Main</Main-Class>
        </manifestEntries>
       </transformer>
     </transformers>

akka-docs/src/main/paradox/project/migration-guide-2.5.x-2.6.x.md

@@ -95,6 +95,11 @@ Warnings about `TypedActor` have been [mentioned in documentation](https://doc.a
 for many years.
 
 
+### akka.Main
+
+`akka.Main` is deprecated in favour of starting the `ActorSystem` from a custom main class instead. `akka.Main` was not
+adding much value and typically a custom main class is needed anyway.
+
 @@ Remoting
 
 ### Default remoting is now Artery TCP