feat: support send knowledge base image

config-template.json

@@ -1,7 +1,7 @@
 {
   "channel_type": "wx",
+  "model": "",
   "open_ai_api_key": "YOUR API KEY",
-  "model": "gpt-3.5-turbo",
   "text_to_image": "dall-e-2",
   "voice_to_text": "openai",
   "text_to_voice": "openai",
@@ -28,7 +28,6 @@
   "speech_recognition": true,
   "group_speech_recognition": false,
   "voice_reply_voice": false,
-  "tts_voice_id": "alloy",
   "conversation_max_tokens": 2500,
   "expires_in_seconds": 3600,
   "character_desc": "你是ChatGPT, 一个由OpenAI训练的大型语言模型, 你旨在回答并解决人们的任何问题，并且可以使用多种语言与人交流。",