docs: temporarily remove the config in template

It will be described later in the document as an optional configuration

config-template.json

@@ -4,7 +4,6 @@
   "single_chat_prefix": ["bot", "@bot"],
   "single_chat_reply_prefix": "[bot] ",
   "group_chat_prefix": ["@bot"],
-  "group_chat_in_one_session": ["ChatGPT测试群"],
   "group_name_white_list": ["ChatGPT测试群", "ChatGPT测试群2"],
   "image_create_prefix": ["画", "看", "找"],
   "conversation_max_tokens": 1000,