Add « to the second "Back to index" button

Author: jpcano

src/layouts/BlogPost.astro

@@ -44,7 +44,7 @@ const ogImage = await getImage({ src: heroImage, format: "jpg", height: 200 });
           <slot />
         </div>
       </article>
-      <a class="index-button" href="/blog">Back to index</a>
+      <a class="index-button" href="/blog">« Back to index</a>
     </div>
   </main>
 </BaseLayout>