refactor: migrate to rsc and app dir

app/about/page.tsx

@@ -0,0 +1,7 @@
+import { allAuthors } from 'contentlayer/generated'
+import About from './About'
+
+export default function Page() {
+  const author = allAuthors.find((p) => p.slug === 'default')
+  return <About author={author} />
+}