add release badge

Author: everesio

README.md

@@ -3,6 +3,7 @@ Casbin JetStream
 
 [![Build](https://github.com/grepplabs/casbin-jetstream/actions/workflows/ci.yml/badge.svg)](https://github.com/grepplabs/casbin-jetstream/actions/workflows/ci.yml)
 [![Godoc](https://godoc.org/github.com/casbin/casbin?status.svg)](https://pkg.go.dev/github.com/grepplabs/casbin-jetstream)
+[![Release](https://img.shields.io/github/v/release/grepplabs/casbin-jetstream?sort=semver)](https://github.com/grepplabs/casbin-jetstream/releases)
 
 Casbin JetStream is the [NATS JetStream](https://docs.nats.io/nats-concepts/jetstream) adapter for [Casbin](https://github.com/casbin/casbin). With this library, Casbin can load policy from JetStream or save policy to it.