Added onDestroy event

ModuleClientAPI.md

@@ -56,6 +56,18 @@ api.finishClientCondition(conditionId);
 
 ## Events
 
+### onDestroy
+
+Register a listener for when the module is destroyed from the scene. Make sure you stop your clocks and render loops here.
+
+```javascript
+api.onDestroy(callback);
+```
+
+| Argument | Type               | Description                                                  |
+| -------- | ------------------ | ------------------------------------------------------------ |
+| callback | ( value:any ):void | Function that will be called when the module gets destroyed. |
+
 ### onPropertyUpdate
 
 Register a listener for when a property updates in a scene change.