New usage case: xiaohongshu.com (#631)

add company usecase of xiaohongshu.com

Signed-off-by: gnolizuh <[email protected]>

README.md

@@ -163,6 +163,7 @@ func main() {
 * [Akvorado](https://github.com/akvorado/akvorado) utilizes Expr to classify exporters and interfaces in network flows.
 * [keda.sh](https://keda.sh) uses Expr to allow customization of its Kubernetes-based event-driven autoscaling.
 * [Span Digital](https://spandigital.com/) uses Expr in it's Knowledge Management products.
+* [Xiaohongshu](https://www.xiaohongshu.com/) combining yaml with Expr for dynamically policies delivery.
 
 [Add your company too](https://github.com/expr-lang/expr/edit/master/README.md)