refact: prefer function over lambdas

src/pages/404.tsx

@@ -3,12 +3,14 @@ import React from "react"
 import Layout from "../components/Layout"
 import SEO from "../components/SEO"
 
-const NotFoundPage = () => (
-  <Layout>
-    <SEO title="404: Not found" />
-    <h1>NOT FOUND</h1>
-    <p>You just hit a route that doesn&#39;t exist... the sadness.</p>
-  </Layout>
-)
+function NotFoundPage() {
+  return (
+    <Layout>
+      <SEO title="404: Not found" />
+      <h1>NOT FOUND</h1>
+      <p>You just hit a route that doesn&#39;t exist... the sadness.</p>
+    </Layout>
+  )
+}
 
 export default NotFoundPage