Fix params order for hydrateRoot reference (#4552)

content/docs/reference-react-dom-client.md

@@ -71,7 +71,7 @@ root.unmount();
 ### `hydrateRoot()` {#hydrateroot}
 
 ```javascript
-hydrateRoot(element, container[, options])
+hydrateRoot(container, element[, options])
 ```
 
 Same as [`createRoot()`](#createroot), but is used to hydrate a container whose HTML contents were rendered by [`ReactDOMServer`](/docs/react-dom-server.html). React will attempt to attach event listeners to the existing markup.