Update examples with `ReactDOM.render()` for React 18

[pReya]

In multiple examples, a DOM element will be created via ReactDOM.render(), which is deprecated in React 18. Would be nice to see a best practice how to solve this in React 18.

[lcurrit]

This worked:
import { createRoot } from "react-dom/client";

Inside the features forEach loop:

  // Render a Marker Component on our new DOM node
  createRoot(ref.current).render(
    <Marker onClick={markerClicked} feature={feature} />
  );

[billThieleMms]

I'm also struggling with this at the moment. I'm trying to add popups to map markers, following the tooltip example from this repository. Haven't found a way of doing it yet without the depcrecated APIs.

[yewyewxd]

Hi @billThieleMms , just to clarify, you want to add markers to the map, and when you hover over those markers, it should show a react tool-tip about the marked place, right?