title: When I use the `hreflang attribute in Link I get warning
body: <pre><code>import React from "react";
  import ReactDOM from "react-dom";
  
  import { BrowserRouter as Router, Link } from "react-router-dom";
  
  function App() {
    return (
      &lt;div className="App"&gt;
        &lt;Router&gt;
          &lt;Link
            hreflang={"en"}
            to={
              "https://www.youtube.com/watch?v=mmCnQDUSO4I&amp;list=RDmmCnQDUSO4I&amp;start_radio=1"
            }
          &gt;
            {"Dmitri Shostakovich"}
          &lt;/Link&gt;
        &lt;/Router&gt;
      &lt;/div&gt;
    );
  }
  
  const rootElement = document.getElementById("root");
  ReactDOM.render(&lt;App /&gt;, rootElement);
  </code></pre>
  
  <p>I'm new to react and react-router. In the console I get this Warning.</p>
  
  <blockquote>
    <p>Warning: Invalid DOM property <code>hreflang</code>. Did you mean <code>hrefLang</code>.</p>
  </blockquote>
  
  <p>Secondly, the link does not work for me.</p>