updated the ux index format

Author: Daniela Caicedo

plugin-design-guidelines/ui_resources/index.md

@@ -15,6 +15,7 @@ The tutorials contained in this section will give you an in-depth look at UI fea
 In this section you can see what styles you can use in the UI, how to build a modal layout and the UI elements you can use.
 
  **Styles**
+
 In this section you can learn more about rich styling options in your user interface through a combination of CSS and various classes that are defined for you.
 
 > **Elements**