Crash if broken tags exist when enabling html

[exKAZUu]

The following code causes the bottom error (in storybook).

  .add('Broken tag', () => (
    <Marp
      options={{
        html: true,
        markdown: {
          breaks: true,
        },
      }}
      markdown={text('Markdown', `<small>aaa`)}
    />
  ))

Cannot read property 'map' of undefined
TypeError: Cannot read property 'map' of undefined
    at render (http://localhost:6006/main.17a86d2330c9200446be.bundle.js:371:107)
    at http://localhost:6006/main.17a86d2330c9200446be.bundle.js:371:118
    at Array.map (<anonymous>)
    at render (http://localhost:6006/main.17a86d2330c9200446be.bundle.js:371:107)
    at http://localhost:6006/main.17a86d2330c9200446be.bundle.js:77:183
    at Array.map (<anonymous>)
    at Marp (http://localhost:6006/main.17a86d2330c9200446be.bundle.js:76:25)
    at renderWithHooks (http://localhost:6006/vendors~main.17a86d2330c9200446be.bundle.js:134899:18)
    at mountIndeterminateComponent (http://localhost:6006/vendors~main.17a86d2330c9200446be.bundle.js:137578:13)
    at beginWork (http://localhost:6006/vendors~main.17a86d2330c9200446be.bundle.js:138692:16)