docs: add og tags

docs/.vitepress/config.ts

@@ -13,6 +13,19 @@ import llmstxt from 'vitepress-plugin-llms'
 const prod = !!process.env.NETLIFY
 const siteUrl = 'https://vitepress.dev'
 
+const ogImage = new URL('/vitepress-og.jpg', siteUrl).href
+
+const localeToOgLocaleMap: Record<string, string> = {
+  root: 'en_US',
+  zh: 'zh_CN',
+  pt: 'pt_BR',
+  ru: 'ru_RU',
+  es: 'es_ES',
+  ko: 'ko_KR',
+  fa: 'fa_IR',
+  ja: 'ja_JP'
+}
+
 export default defineConfig({
   title: 'VitePress',
 
@@ -83,9 +96,6 @@ export default defineConfig({
     ['link', { rel: 'icon', type: 'image/svg+xml', href: '/vitepress-logo-mini.svg' }],
     ['link', { rel: 'icon', type: 'image/png', href: '/vitepress-logo-mini.png' }],
     ['meta', { name: 'theme-color', content: '#5f67ee' }],
-    ['meta', { property: 'og:type', content: 'website' }],
-    ['meta', { property: 'og:site_name', content: 'VitePress' }],
-    ['meta', { property: 'og:image', content: new URL('/vitepress-og.jpg', siteUrl).href }],
     ['script', { src: 'https://cdn.usefathom.com/script.js', 'data-site': 'AZBRSFGG', 'data-spa': 'auto', defer: '' }]
   ],
 
@@ -145,15 +155,24 @@ export default defineConfig({
   transformPageData: prod ? (pageData, ctx) => {
     const url = new URL(pageData.relativePath.replace(/(?:(^|\/)index)?\.md$/, '$1'), siteUrl).href
     const site = resolveSiteDataByRoute(ctx.siteConfig.site, pageData.relativePath)
-    const locale = site.lang.replace(/-([a-z]+)$/i, '_$1')
-    const title = `${pageData.title || site.title} | VitePress`
+    const title = pageData.title ? `${pageData.title} | VitePress` : site.title
     const description = pageData.description || site.description
+    const locale = localeToOgLocaleMap[site.localeIndex || 'root']
 
     ;((pageData.frontmatter.head ??= []) as HeadConfig[]).push(
       ['meta', { property: 'og:url', content: url }],
-      ['meta', { property: 'og:locale', content: locale }],
       ['meta', { property: 'og:title', content: title }],
-      ['meta', { property: 'og:description', content: description }]
+      ['meta', { property: 'og:description', content: description }],
+      ['meta', { property: 'og:type', content: 'website' }],
+      ['meta', { property: 'og:locale', content: locale }],
+      ['meta', { property: 'og:site_name', content: 'VitePress' }],
+      ['meta', { property: 'og:image', content: ogImage }],
+      ['meta', { property: 'og:image:secure_url', content: ogImage }],
+      ['meta', { property: 'og:image:type', content: 'image/jpeg' }],
+      ['meta', { property: 'og:image:width', content: '1280' }],
+      ['meta', { property: 'og:image:height', content: '640' }],
+      ['meta', { property: 'og:image:alt', content: 'VitePress' }],
+      ['link', { rel: 'canonical', href: url }]
     )
   } : undefined
 })