i18n(es): Update api-reference.md (withastro#2006)

src/pages/es/reference/api-reference.md

@@ -26,7 +26,7 @@ const posts = await Astro.glob('../pages/post/*.md'); // devuelve un array de ar
   <article>
     <h1>{post.frontmatter.title}</h1>
     <p>{post.frontmatter.description}</p>
-    <a href={post.frontmatter.url}>Read more</a>
+    <a href={post.url}>Read more</a>
   </article>
 ))}
 </div>