Update CHANGELOG.md (Azure#16671)

looks like beta-2 is not yet released

sdk/web-pubsub/web-pubsub-express/CHANGELOG.md

@@ -1,8 +1,24 @@
 # Release History
 
-## 1.0.0-beta.3 (UNRELEASED)
+## 1.0.0-beta.3 (2021-07-30)
 
-- Add support to get and set connection state
+- Support reading and setting connection states, sample usage:
+ ```js
+ const handler = new WebPubSubEventHandler("chat", ["https://xxx.webpubsub.azure.com"], {
+ handleConnect(req, res) {
+ // You can set the state for the connection, it lasts throughout the lifetime of the connection
+ res.setState("calledTime", 1);
+ res.success();
+ },
+ handleUserEvent(req, res) {
+ var calledTime = req.context.states.calledTime++;
+ console.log(calledTime);
+ // You can also set the state here
+ res.setState("calledTime", calledTime);
+ res.success();
+ }
+ });
+ ```
 
 ## 1.0.0-beta.2 (2021-07-20)