code: async def update_emoji(**payload):
      
      data = payload["data"]
      web_client = payload["web_client"]
      channel_id = data["item"]["channel"]
      user_id = data["user"]
  
      # Get the original tutorial sent.
      onboarding_tutorial = onboarding_tutorials_sent[channel_id][user_id]
  
      # Mark the reaction task as completed.
      onboarding_tutorial.reaction_task_completed = True
  
      # Get the new message payload
      message = onboarding_tutorial.get_message_payload()
  
      # Post the updated message in Slack
      updated_message = await web_client.chat_update(**message)
  
      # Update the timestamp saved on the onboarding tutorial object
      onboarding_tutorial.timestamp = updated_message["ts"]
docs: Update the onboarding welcome message after recieving a "reaction_added"
      event from Slack. Update timestamp for welcome message as well.