update rendering-elements page

pages/docs/react/latest/rendering-elements.mdx

@@ -43,9 +43,12 @@ Here is a full example rendering our application in our `root` div:
 ```res
 // Dom access can actually fail. ReScript
 // is really explicit about handling edge cases!
-switch(ReactDOM.querySelector("#root")){
-| Some(root) => ReactDOM.render(<div> {React.string("Hello Andrea")} </div>, root)
-| None => () // do nothing
+switch ReactDOM.querySelector("#root") {
+| Some(rootElement) => {
+    let root = ReactDOM.Client.createRoot(rootElement)
+    ReactDOM.Client.Root.render(root, <div />)
+  }
+| None => ()
 }
 ```
 ```js
@@ -60,6 +63,6 @@ if (!(root == null)) {
 
 React elements are immutable. Once you create an element, you can’t change its children or attributes. An element is like a single frame in a movie: it represents the UI at a certain point in time.
 
-At this point we would need to understand a few more concepts, such as React components and state management to be able to update the rendered elements after the initial `ReactDOM.render`. For now, just imagine your React application as a tree of elements, whereby some elements may get replaced during the lifetime of your application.
+At this point we would need to understand a few more concepts, such as React components and state management to be able to update the rendered elements after the initial `ReactDOM.Client.Root.render`. For now, just imagine your React application as a tree of elements, whereby some elements may get replaced during the lifetime of your application.
 
 React will automatically recognize any element changes and will only apply the DOM updates necessary to bring the DOM to the desired state.