fix: former page no longer available.

change broken link with more detailed link.

Author: YukiCoco

readme.md

@@ -29,7 +29,10 @@
 需要在 `github/workflows/*.yml` 中，修改这个配置
 
 <details><summary>如何找到 NOTION_API_KEY？</summary>
-请参考：https://www.notion.so/Add-and-manage-integrations-with-the-API-910ac902372042bc9da38d48171269cd#eeaa235ffe834d4f9a89a5893398f341
+请参考：https://www.notion.so/help/create-integrations-with-the-notion-api#create-an-internal-integration
+
+创建 internal integration 之后，需要给予这个 token 访问 database 的权限  
+请参考：https://developers.notion.com/docs/create-a-notion-integration#give-your-integration-page-permissions  
 </details>
 
 <details><summary>如何找到 NOTION DATABASE ID</summary>