Function dragStart

src/App/Components/Markdown/DragBar.js:6–10

const UnwrappedDragBar = ({ className, setDrag, setStartX }) => {
  const dragStart = e => {
    const { nativeEvent } = e;
    const offsetX = nativeEvent.offsetX;
    setStartX(offsetX);
  };
  return (
    <div
      className={className}