Add warning for ReactDOMRe

Author: ryyppy

pages/docs/react/latest/elements-and-jsx.mdx

@@ -190,6 +190,7 @@ ReactDOMRe.createDOMElementVariadic("div", ~props=ReactDOM.domProps(~className="
 
 The function above requires the `ReactDOM.domProps` constructor function, so ReScript can make sure that we are only passing valid dom props. You can find an exhaustive list of all available props in the [ReactDOM](https://github.com/reasonml/reason-react/blob/master/src/ReactDOM.re#L61) module.
 
+**Warning:** The `ReactDOMRe` module will be removed in the next major `rescript-react` release, so use sparsely!
 
 ### Cloning Elements
 
@@ -221,4 +222,3 @@ React.cloneElement(original, {
 The feature mentioned above could also replicate `props spreading`, a practise commonly used in ReactJS codebases, but we strongly discourage the usage due to its unsafe nature and its incorrectness (e.g. adding undefined extra props to a component doesn't make sense, and causes hard to find bugs).
 
 In ReScript, we rather pass down required props explicitly to leaf components or use a renderProp instead. We introduced [JSX punning](/docs/manual/latest/jsx#punning) syntax to make the process of passing down props more convenient.
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