storybook/docs/snippets/react/page-story-slots.js.mdx

```js
// Page.stories.js | Page.stories.jsx

import React from 'react';

import { Page } from './Page';

export default {
  component: Page,
};

export const CustomFooter = {
  args: {
    footer: 'Built with Storybook',
  },
  render: (args) => (
    <Page {...args}>
      <footer>{args.footer}</footer>
    </Page>
  ),
};
```