#22903 Fix code snippeds

* move scala and java sources out of paradox sources
* replace relative paths with $code$ and $akka$
* fix broken includes

akka-docs/src/main/scala/docs/stream/cookbook/RecipeSimpleDrop.scala

@@ -0,0 +1,50 @@
+package docs.stream.cookbook
+
+import akka.NotUsed
+import akka.stream.scaladsl.{ Flow, Sink, Source }
+import akka.stream.testkit._
+import scala.concurrent.duration._
+import akka.testkit.TestLatch
+import scala.concurrent.Await
+
+class RecipeSimpleDrop extends RecipeSpec {
+
+  "Recipe for simply dropping elements for a faster stream" must {
+
+    "work" in {
+
+      //#simple-drop
+      val droppyStream: Flow[Message, Message, NotUsed] =
+        Flow[Message].conflate((lastMessage, newMessage) => newMessage)
+      //#simple-drop
+      val latch = TestLatch(2)
+      val realDroppyStream =
+        Flow[Message].conflate((lastMessage, newMessage) => { latch.countDown(); newMessage })
+
+      val pub = TestPublisher.probe[Message]()
+      val sub = TestSubscriber.manualProbe[Message]()
+      val messageSource = Source.fromPublisher(pub)
+      val sink = Sink.fromSubscriber(sub)
+
+      messageSource.via(realDroppyStream).to(sink).run()
+
+      val subscription = sub.expectSubscription()
+      sub.expectNoMsg(100.millis)
+
+      pub.sendNext("1")
+      pub.sendNext("2")
+      pub.sendNext("3")
+
+      Await.ready(latch, 1.second)
+
+      subscription.request(1)
+      sub.expectNext("3")
+
+      pub.sendComplete()
+      subscription.request(1)
+      sub.expectComplete()
+    }
+
+  }
+
+}