feat(seo): ✨ alternate languages in sitemap

src/utils/Sitemap.ts

@@ -1,6 +1,7 @@
+import nextConfig from '../../next.config';
 export function generateSiteMap(content: string) {
 	return `<?xml version="1.0" encoding="UTF-8"?>
-            <urlset xmlns="http://www.sitemaps.org/schemas/sitemap/0.9">
+            <urlset xmlns="http://www.sitemaps.org/schemas/sitemap/0.9" xmlns:xhtml="http://www.w3.org/1999/xhtml">
                 ${content}
             </urlset>`;
 }
@@ -11,10 +12,14 @@ export function generateSiteMapContent(
 	return data
 		.map(
 			(d) => `<url>
-                        <loc>${`http://buildtheearth.net${d.loc}`}</loc>
+                        <loc>${`https://buildtheearth.net${d.loc}`}</loc>
                         <lastmod>${d.lastModified.toISOString().split('T')[0]}</lastmod>
-                        <changefreq>${d.changeFrequency}</changefreq>
-                        <priority>${d.priority}</priority>
+                        ${nextConfig.i18n?.locales
+													.map(
+														(locale) =>
+															` <xhtml:link rel="alternate" hreflang="${locale}" href="https://buildtheearth.net/${locale}${d.loc}"/>`,
+													)
+													.join('')}
                     </url>`,
 		)
 		.join('');