added docs for async list Actors function

Author: protoss70

src/apify_client/clients/resource_clients/actor_collection.py

@@ -163,6 +163,7 @@ async def list(
             limit: How many Actors to list.
             offset: What Actor to include as first when retrieving the list.
             desc: Whether to sort the Actors in descending order based on their creation date.
+            sort_by: Field to sort the results by. Allowed values are "createdAt" and "lastRunStartedAt".
 
         Returns:
             The list of available Actors matching the specified filters.