Docs for Scene methods

Added descriptions and arguments.

src/scene/Scene.js

@@ -269,9 +269,9 @@ var Scene = new Class({
 
     /**
      * Should be overridden by your own Scenes.
+     * This method is called once per game step while the scene is running.
      *
      * @method Phaser.Scene#update
-     * @override
      * @since 3.0.0
      *
      * @param {number} time - The current time. Either a High Resolution Timer value if it comes from Request Animation Frame, or Date.now if using SetTimeout.
@@ -282,27 +282,33 @@ var Scene = new Class({
     }
 
     /**
-     * Should be overridden by your own Scenes.
+     * Can be defined on your own Scenes.
+     * This method is called by the Scene Manager when the scene starts, before `preload()` and `create()`.
      *
      * @method Phaser.Scene#init
-     * @override
      * @since 3.0.0
+     *
+     * @param {object} data - Any data passed via `ScenePlugin.add()` or `ScenePlugin.start()`. Same as Scene.settings.data.
      */
 
     /**
-     * Should be overridden by your own Scenes.
+     * Can be defined on your own Scenes. Use it to load assets.
+     * This method is called by the Scene Manager, after `init()` and before `create()`, only if the Scene has a LoaderPlugin.
+     * After this method completes, if the LoaderPlugin's queue isn't empty, the LoaderPlugin will start automatically.
      *
      * @method Phaser.Scene#preload
-     * @override
      * @since 3.0.0
      */
 
     /**
-     * Should be overridden by your own Scenes.
+     * Can be defined on your own Scenes. Use it to create your game objects.
+     * This method is called by the Scene Manager when the scene starts, after `init()` and `preload()`.
+     * If the LoaderPlugin started after `preload()`, then this method is called only after loading is complete.
      *
      * @method Phaser.Scene#create
-     * @override
      * @since 3.0.0
+     *
+     * @param {object} data - Any data passed via `ScenePlugin.add()` or `ScenePlugin.start()`. Same as Scene.settings.data.
      */
 
 });