update README.md

README.md

 
 First of all, please open or create a Unity Project and open it with Unity Editor. 
 
+And then open Project Settings, go to Player section and add "UIWidgets_DEBUG" to the Scripting Debug Symbols field.
+This enables the debug mode of UIWidgets for your development. Remove this for your release build afterwards.
+
 #### ii. Scene Build
 A UIWidgets App is usually built upon a Unity UI Canvas. Please follow the steps to create a
 UI Canvas in Unity.
     
     namespace UIWidgetsSample {
         public class ExampleCanvas : WidgetCanvas {
+            protected override void OnEnable() {
+                base.OnEnable();
+                    
+                // Application.targetFrameRate = 60; // or higher if you want a smoother scrolling experience.
+                
+                // if you want to use your own font or font icons.
+                // use the font family name instead of the file name in FontStyle.fontFamily.
+                // you can get the font family name by clicking the font file and check its Inspector.                 
+                // FontManager.instance.addFont(Resources.Load<Font>(path: "path to your font"));                
+            }
+                
             protected override Widget getWidget() {
                 return new ExampleApp();
             }
 1. Choose a target platform and click "Build". Then the Unity Editor will automatically assemble 
 all relevant resources and generate the final App package.
 
+#### How to load images?
+1. Put your images files in Resources folder. e.g. image1.png.
+2. You can add image1@2.png and image1@3.png in the same folder to support HD screens.
+3. Use Image.asset("image1") to load the image. Note: as in Unity, ".png" is not needed.
+
+UIWidgets supports Gif as well!
+1. Suppose you have loading1.gif. Rename it to loading1.gif.bytes and copy it to Resources folder.
+2. You can add loading1@2.gif.bytes and loading1@3.gif.bytes in the same folder to support HD screens.
+3. Use Image.asset("loading1.gif") to load the gif images.
 
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