updated the styling for the UI index page

Author: Daniela Caicedo

plugin-design-guidelines/ui_resources/index.md

@@ -14,7 +14,7 @@ The tutorials contained in this section will give you an in-depth look at UI fea
 ## UI Components
 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.
+**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** - see what elements are fundamental to your user interface.