How to use the idyll-components.Header function in idyll-components

liveExample: true
          }
        },
        {
          Gist: {
            thumbnail: 'gist.png',
            component: COMPONENTS.Gist,
            description: 'Embed a github gist',
            image: 'gist.png',
            liveExample: true
          }
        },
        {
          Header: {
            thumbnail: 'header.png',
            component: COMPONENTS.Header,
            description:
              'This component makes it easy to add a title, subtitle, and byline to your article:',
            image: 'header.png',
            liveExample: true
          }
        },
        {
          Link: {
            thumbnail: 'link.png',
            component: COMPONENTS.Link,
            description:
              'This component just acts as syntactic sugar for displaying links inline in your text.',
            liveExample: true
          }
        },
        {