修复二级菜单编译bug

lib/notion/getPageProperties.js

@@ -98,7 +98,7 @@ export default async function getPageProperties(id, block, schema, authToken, ta
     properties.slug = properties.slug ?? properties.id
   } else if (properties.type === BLOG.NOTION_PROPERTY_NAME.type_menu || properties.type === BLOG.NOTION_PROPERTY_NAME.type_sub_menu) {
     // 菜单路径为空、作为可展开菜单使用
-    properties.to = properties.slug ?? null
+    properties.to = properties.slug ?? '#'
     properties.name = properties.title ?? ''
   }