Renderer of an actual block of type `block`. Confusing, we know.
function BlockTypeSerializer(props) {
    const style = props.node.style || 'normal'

    if (/^h\d/.test(style)) {
      return h(style, null, props.children)
    }

    return style === 'blockquote'
      ? h('blockquote', null, props.children)
      : h('p', null, props.children)
  }