#1006 Update parameter description in chat_action.py

The comment describing the 'initial_sleep' parameter in the chat_action.py script has been revised for clarity. It now accurately specifies this parameter's purpose as the waiting period prior to the first sending of the action, rather than just the first iteration.

aiogram/utils/chat_action.py

@@ -43,7 +43,7 @@ def __init__(
         :param chat_id: target chat id
         :param action: chat action type
         :param interval: interval between iterations
-        :param initial_sleep: sleep before first iteration
+        :param initial_sleep: sleep before first sending of the action
         """
         self.chat_id = chat_id
         self.message_thread_id = message_thread_id