update CHANGELOG and create websocker-server instructions

examples/websocket-server/README.md

@@ -0,0 +1,27 @@
+# Websocket Server
+
+This is an example that shows how to use `WebsocketServerTransport` to communicate with a web client.
+
+## Get started
+
+```python
+python3 -m venv venv
+source venv/bin/activate
+pip install -r requirements.txt
+```
+
+## Run the server
+
+```bash
+python server.py
+```
+
+## Run the HTTP server
+
+This will host the static web client:
+
+```bash
+python -m http.server
+```
+
+Then, visit `http://localhost:8000` in your browser to start a session.