添加mermaid图表接口 (#85)

* 添加mermaid图表接口

* 添加类型文件

* Update package.json

* Create next-env.d.ts

client/next-env.d.ts

@@ -0,0 +1,5 @@
+/// <reference types="next" />
+/// <reference types="next/image-types/global" />
+
+// NOTE: This file should not be edited
+// see https://nextjs.org/docs/basic-features/typescript for more information.