Update TextChatService API reference to call attention to new TextCha… (

#904)

…nnel-related feature

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

@@ -218,6 +218,8 @@ properties:
       `Class.TextChannel|TextChannels` even if
       `Class.TextChatService.CreateDefaultTextChannels|CreateDefaultTextChannels`
       is true.
+      
+      Messages from different TextChannels can be separated into different tabs in the chat window using `Class.ChannelTabsConfiguration`.
     code_samples: []
     type: bool
     tags: []