title: react is not updating functional component state on input change
body: <p>When i type input and on change editing.hours doesn't update input value but i see updated value in the console.</p>
  
  <pre><code>const nullableEntry = {
      ID: '',
      day: '',
      hours: 0.0,
      note: '',
  };
  
  const MonthTable = (props) =&gt; {
      const [editing, setEditing] = useState(nullableEntry);
  
      function handleHoursInput(e) {
          editing.hours = e.target.value;
          setEditing(editing);
      }
  
      return (
         &lt;input type="number" value={editing.hours} step="0.01" onChange={handleHoursInput} className="form-control" name="" /&gt;
      );
  };
  
  export default MonthTable;
  </code></pre>