fix: typos

app.py

@@ -481,7 +481,7 @@ def validate_challenge(response, input, state):
             else:
                 challenge_result = 'All Challenges Completed!'
     else:
-        challenge_result = 'challenge failed，please retry'
+        challenge_result = 'challenge failed, please retry'
     state['current_chapter_index'] = current_chapter_index
     state['current_challenge_index'] = current_challenge_index
     print('update state: ', state)
@@ -531,7 +531,7 @@ with block as demo:
     current_chapter_index = 0
     current_challenge_index = 0
     gr.Markdown("""<center><font size=6>Darn! Ambushed by LLMs!</center>""")
-    gr.Markdown("""<font size=3>Welcome to the LLM Riddles Replica Edition，[Thank Haoqiang Fan's idea](https://zhuanlan.zhihu.com/p/665393240): Darn! Ambushed by LLMs!
+    gr.Markdown("""<font size=3>Welcome to the LLM Riddles Replica Edition, [Thank Haoqiang Fan's idea](https://zhuanlan.zhihu.com/p/665393240): Darn! Ambushed by LLMs!
 
 Through this game, you will gain a deeper understanding of large language models.