Update topics_group_message.md

Author: WizardLoop

examples/topics_group_message.md

@@ -1,12 +1,12 @@
 # topics group message
 
 ## valid format to use
-**public:** 
+**public chat:** 
 ```https://t.me/username/id```
 
 _username group + message id_
 
-**private:** 
+**private chat:** 
 ```https://t.me/c/id/id```
 
 _id group + message id_