404 page

src/pages/404.js

@@ -0,0 +1,17 @@
+import React from "react";
+import Layout from "../components/layout"
+
+export default function NotFound() {
+    return (
+        <Layout>
+            <h1>404 : Page not found</h1>
+            <p>
+                Sorry, we've misplaced that URL or it's pointing
+                to something that doesn't exist.
+            </p>
+            <p>                
+                <a href="/">Head back home</a> to try finding it again.
+            </p>
+        </Layout>
+    )
+}