Update manifest-dev.json

Author: canisminor1990

public/manifest-dev.json

@@ -24,7 +24,7 @@
     "properties": {
       "SERPAPI_API_KEY": {
         "title": "SerpAPI API Key",
-        "description": "we use SerpAPI as backend service [Learn more](https://github.com/lobehub/chat-plugin-search-engine) | 该插件使用 SerpAPI 作为搜索服务",
+        "description": "we use [SerpAPI](https://serpapi.com) as backend service | 该插件使用 SerpAPI 作为搜索服务",
         "type": "string",
         "minLength": 64,
         "maxLength": 64,