Update ChannelTabsConfiguration API reference to point to guide docs on the feature

Author: teresayangg

content/en-us/reference/engine/classes/ChannelTabsConfiguration.yaml

@@ -7,6 +7,8 @@ summary: |
 description: |
   Configures properties of the optional channel tabs in the default chat window.
   It is parented to `Class.TextChatService`.
+
+  To learn more, see [Customizing Text Chat](../../../chat/customizing-in-experience-text-chat.md).
 code_samples: []
 inherits:
   - TextChatConfigurations