add default prompt to web search

lang/en-US.json

@@ -35,6 +35,7 @@
   "delete": "Delete",
   "signOut": "Sign out",
   "webSearch": "Web Search",
+  "webSearchDefaultPrompt": "Web search results:\n\n{web_results}\nCurrent date: {current_date}\n\nInstructions: Using the provided web search results, write a comprehensive reply to the given query. Make sure to cite results using [[number](URL)] notation after the reference. If the provided search results refer to multiple subjects with the same name, write separate answers for each subject.\nQuery: {query}",
   "welcomeScreen": {
     "introduction1": "is an unofficial client for ChatGPT, but uses the official OpenAI API.",
     "introduction2": "You will need an OpenAI API Key before you can use this client.",

lang/zh-CN.json

@@ -35,6 +35,7 @@
   "delete": "删除",
   "signOut": "退出登录",
   "webSearch": "网页搜索",
+  "webSearchDefaultPrompt": "网络搜索结果：\n\n{web_results}\n当前日期：{current_date}\n\n说明：使用提供的网络搜索结果，对给定的查询写出全面的回复。确保在引用参考文献后使用 [[number](URL)] 符号进行引用结果. 如果提供的搜索结果涉及到多个具有相同名称的主题，请针对每个主题编写单独的答案。\n查询：{query}",
   "welcomeScreen": {
     "introduction1": "是一个非官方的ChatGPT客户端，但使用OpenAI的官方API",
     "introduction2": "在使用本客户端之前，您需要一个OpenAI API密钥。",