code: function splitListItem(opts: Options, change: Change): Change {
      const { value } = change;
      const currentItem = getCurrentItem(opts, value);
      if (!currentItem) {
          return change;
      }
  
      const splitOffset = value.startOffset;
  
      return change.splitDescendantsByKey(
          currentItem.key,
          value.startKey,
          splitOffset
      );
  }
docs: Split a list item at the start of the current range.