From 43fac04cdc4fd90a37a44154230ce3b050831a22 Mon Sep 17 00:00:00 2001
From: Xavi Lee <awxiaoxian2020@163.com>
Date: Wed, 24 Jan 2024 09:19:02 +0800
Subject: [PATCH] sync with
 https://github.com/vuejs/vitepress/commit/9510cd70c14ce9a80962ade5dd1702f7d2e2218e

---
 docs/zh/reference/site-config.md | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)

diff --git a/docs/zh/reference/site-config.md b/docs/zh/reference/site-config.md
index a2814a95..9b48f1ed 100644
--- a/docs/zh/reference/site-config.md
+++ b/docs/zh/reference/site-config.md
@@ -645,6 +645,23 @@ export default {
 }
 ```
 
+#### 示例：添加一个典型的 URL `<link>` {#example-adding-a-canonical-url-link} 
+
+```ts
+export default {
+  transformHead({ page }) {
+    // Skip the 404 page
+    if (page !== '404.md') {
+      const canonicalUrl = `https://example.com/${page}`
+        .replace(/index\.md$/, '')
+        .replace(/\.md$/, '.html')
+
+      return [['link', { rel: 'canonical', href: canonicalUrl }]]
+    }
+  }
+}
+```
+
 ### transformHtml
 
 - 类型：`(code: string, id: string, context: TransformContext) => Awaitable<string | void>`