render on root not app (#1361)

Co-authored-by: yousif1997 <42901524+yousif1997@users.noreply.github.com>

Author: fullmooner-stack

src/routes/solid-router/reference/components/router.mdx

@@ -32,7 +32,7 @@ const App = (props) => (
 
 render(
 	() => <Router root={App}>{/*... routes */}</Router>,
-	document.getElementById("app")
+	document.getElementById("root")
 );
 ```