feat: add catch all route and pages for 404 and 500 errors

src/app/not-found.tsx

@@ -0,0 +1,15 @@
+import Link from 'next/link.js';
+import styles from './error.module.css';
+
+export default function Page() {
+  return (
+    <div className={styles.container}>
+      <h1>
+        Oops! The page you are trying to view does not exist
+      </h1>
+      <Link className={styles.navLink} href="/">
+        Go to the home page
+      </Link>
+    </div>
+  );
+}