add scriptable object examples

add editor window example
add attribute + drawer example

EditorCustomization/Assets/Scripts/Events/EventBroker.cs

@@ -0,0 +1,13 @@
+using System;
+using UnityEngine;
+
+namespace Events
+{
+    [CreateAssetMenu(fileName = "EventBroker", menuName = "Events/Event Broker", order = 0)]
+    public class EventBroker : ScriptableObject
+    {
+        public event Action PlayerDied;
+        
+        public void RaisePlayerDied() => PlayerDied?.Invoke();
+    }
+}