feat(workers): auto-generated social thumbnails

set the value of og:image per page

workers/auto-locale.js

@@ -62,5 +62,18 @@ async function handleRequest(request) {
     }
   }
 
-  return fetch(request);
+  /* Per-page social thumbnails (og:image) */
+  const response = await fetch(request);
+  if (response.headers.get('Content-type').startsWith('text/html')) {
+    const text = await response.text();
+    return new Response(
+      text.replaceAll(
+        'https://docs.wokwi.com/img/wokwi-book.jpg',
+        `https://thumbs.wokwi.com/docs${pathname}/thumbnail.png`,
+      ),
+      response,
+    );
+  }
+
+  return response;
 }