update document to enable ws & rustls / openssl if user wants to use websockets
@@ -29,7 +29,7 @@ println!("Got code: {}", serde_json::to_string(&code)?);
# Websockets
-The crate has support for WebSockets via Tokio.
+The crate has support for WebSockets via Tokio. Please ensure that you have the "ws" and "rustls" / "openssl" features enabled if you wish to use WebSockets.
```
# async fn foo() -> Result<(), Box<dyn std::error::Error>> {
