Clarity around the sender/receiver in ShouldDeliverCallback.

Author: MaximumADHD

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

@@ -293,17 +293,21 @@ callbacks:
       returns anything else (including `nil`), the message won't be delivered to
       that client, although the sender will see the message regardless.
 
-      The sender can be referenced by `Class.TextChatMessage.TextSource`.
+      The sender can be referenced by `Class.TextChatMessage.TextSource`. The 
+      receiver is the `textSource` argument. Note that the sender and receiver
+      can be the same, as the callback iterates through all possible receivers.
+      In Roblox Studio, you will be the only sender and recipient of a message
+      while in Play Solo mode.
     code_samples: []
     parameters:
       - name: message
         type: TextChatMessage
         default:
-        summary: ''
+        summary: 'The message being sent, which also contains the sender of the message.'
       - name: textSource
         type: TextSource
         default:
-        summary: ''
+        summary: 'The `Class.TextSource` of the user who will be receiving the message.'
     returns:
       - type: Tuple
         summary: ''