Add RSS links to each post

src/pages/post/[...slug].astro

@@ -56,6 +56,16 @@ const { Content } = await render(post);
                         <Icon name="arrow-left" class="text-lg" />
                         Back
                     </a>
+
+                    {/* RSS feed button */}
+                    <a
+                        href="/feed"
+                        class="btn btn-outline btn-primary btn-sm font-bold"
+                        aria-label="RSS Feed"
+                    >
+                        <Icon name="rss" class="text-lg" />
+                        RSS
+                    </a>
                 </div>
 
                 {