code: function handleHardNewlineEvent(editorState: EditorState): EditorState {
    const selection = editorState.getSelection();
    if (selection.isCollapsed()) {
      const contentState = editorState.getCurrentContent();
      const blockKey = selection.getStartKey();
      const block = contentState.getBlockForKey(blockKey);
      if (
        !isListBlock(block) &&
        block.getType() !== 'unstyled' &&
        block.getLength() === selection.getStartOffset()
      ) {
        return insertNewUnstyledBlock(editorState);
      } else if (isListBlock(block) && block.getLength() === 0) {
        const depth = block.getDepth();
        if (depth === 0) {
          return removeSelectedBlocksStyle(editorState);
        }
        if (depth > 0) {
          return changeListDepth(editorState, -1, depth);
        }
      }
    }
    return undefined;
  }
docs: Function will handle followind keyPress scenarios when Shift key is not pressed.