add documentation

apps/docs/src/components/device-id-warning.tsx

@@ -0,0 +1,12 @@
+import Link from 'next/link';
+import { Callout } from 'nextra/components';
+
+export function DeviceIdWarning() {
+  return (
+    <Callout>
+      Read more about{' '}
+      <Link href="/docs/device-id">device id and why you might want it</Link>.
+      **We recommend not to but it's up to you.**
+    </Callout>
+  );
+}