function convertCodeBlock(node) {
    return {
      ...node,
      type: 'code-block',
      data: {
        ...node.data,
        ...node.data.shortcodeData,
      },
    };
  }
A node with a code mark will be a text node, and will not be adjacent
to a sibling code node as the Slate schema requires them to be
merged. Markdown also requires at least a space between inline code
nodes.