storybook/docs/snippets/common/component-story-custom-source.js.mdx

```js
// Button.stories.js | Button.stories.jsx | Button.stories.ts | Button.stories.tsx

import { Button } from './Button';

export default {
  component: Button,
};

export const CustomSource = {
  parameters: {
    docs: {
      source: {
        code: 'Some custom string here',
      },
    },
  },
};
```