Fix typo (#48)

Co-authored-by: Yazhou Cao <[email protected]>

vision_agent/agent/vision_agent.py

@@ -464,7 +464,7 @@ def chat_with_workflow(
  break
  else:
  reflections += reflection
- # '<END>' is a symbol to indicate the end of the chat, which is useful for streaming logs.
+ # '<ANSWER>' is a symbol to indicate the end of the chat, which is useful for streaming logs.
  self.log_progress(
  f"The Vision Agent has concluded this chat. <ANSWER>{final_answer}</<ANSWER>"
  )