How to: Monitoring a WebSocket endpoint
By prefixing `endpoints[].url` with `ws://` or `wss://`, you can monitor WebSocket endpoints:
```yaml
endpoints:
  - name: example
    url: "wss://echo.websocket.org/"
    body: "status"
    conditions:
      - "[CONNECTED] == true"
      - "[BODY] == pat(*served by*)"
```

The `[BODY]` placeholder contains the output of the query, and `[CONNECTED]`
shows whether the connection was successfully established. You can use Go template
syntax.