add a new phrase

website/pages/docs/guides/design-token.mdx

@@ -86,7 +86,7 @@ final docTheme = MixThemeData(
 
 Mix allows you to define dynamic themes, which means that the values of the design tokens can be resolved dynamically using a [BuildContext](https://api.flutter.dev/flutter/widgets/BuildContext-class.html). To do this, you need to use the `ColorResolver`, `TextStyleResolver`, `RadiusResolver`, `SpaceResolver` and `BreakpointResolver` classes. These classes are used to resolve the values of the design tokens based on the current `BuildContext`.
 
-For example:
+As an example, let's say you want to define a `surface` color token that changes based on the platform brightness. You can do this by using the `ColorResolver` class:
 
 ```dart
 final surface = ColorToken('surface');