React DOM manipulation

Dummy example of using a React ref This example is useless and to the end user seems functionally equivalent to react/hello.html.

It does however serve as a good example of what react does that is useful: it provides a "clear" separation between state and render code (which becomes once again much less clear in React function components.

Notably, this example is insane because at: we are extracing state from some random HTML string rather than having a clean JavaScript variable containing that value.

In this case we managed to get away with it, but this is in general not easy/possible.

React function component version of react/ref-click-counter.html using useRef.