`<CardHeader />` component example:

```js
import {
  Card,
  CardBlock,
  CardTitle,
  CardHeader,
  CardText,
  Button,
} from '$PACKAGE_NAME';

<Card width="50%">
  <CardHeader>Header</CardHeader>
  <CardBlock>
    <CardTitle>Special Title Treatment</CardTitle>
    <CardText>With supporting text below as a natural lead-in to additional content.</CardText>
    <Button color="danger">Click Me</Button>
  </CardBlock>
</Card>
```
