🥅 Add 404 error page

public/locales/en/layout/errors/not-found.json

@@ -0,0 +1,5 @@
+{
+    "title": "Page not found",
+    "text": "This page could not be found. The URL for this page may have expired, the URL is invalid or you do now have the required permissions to access this resource.",
+    "button": "Go to Home"
+}