Update the help text

you-died.py

@@ -44,7 +44,7 @@ def overlay_document(update: Update, context: CallbackContext):
         context.bot.send_message(chat_id=update.effective_chat.id, text="Something went wrong. That might not have been an image.")
 
 def echo(update: Update, context: CallbackContext):
-    context.bot.send_message(chat_id=update.effective_chat.id, text="Send an image (inline or as a file)")
+    context.bot.send_message(chat_id=update.effective_chat.id, text="Send an image (inline or as a file). You can customize the text by adding a caption.")
 
 if __name__ == "__main__":
     try: