Add not-found and loading files

Author: MariferVL

src/app/blog/not-found.js

@@ -0,0 +1,11 @@
+import Link from 'next/link'
+ 
+export default function NotFound() {
+  return (
+    <div>
+      <h2>Not Found</h2>
+      <p>Could not find requested resource</p>
+      <Link href="/">Regresar al Inicio</Link>
+    </div>
+  )
+}

src/app/feed/loading.js

@@ -0,0 +1,4 @@
+export default function Loading() {
+    // Or a custom loading skeleton component
+    return <p>Loading...</p>
+  }