read.me and the diagram is added

event-queue/etc/event-queue.urm.puml

@@ -0,0 +1,26 @@
+@startuml
+package com.iluwatar.event.queue {
+  class App {
+    + App()
+    + getAudioStream(filePath : String) : AudioInputStream {static}
+    + main(args : String[]) {static}
+  }
+  class Audio {
+    - MAX_PENDING : int {static}
+    - headIndex : int {static}
+    - pendingAudio : PlayMessage[] {static}
+    - tailIndex : int {static}
+    - updateThread : Thread {static}
+    + Audio()
+    + init() {static}
+    + playSound(stream : AudioInputStream, volume : float) {static}
+    + stopService() {static}
+    + update() {static}
+  }
+  class PlayMessage {
+    ~ stream : AudioInputStream
+    ~ volume : float
+    + PlayMessage()
+  }
+}
+@enduml