jsdoc @example directive is broken: no syntax highlighting

[paulmillr]

Consider this JS/ts code:

/**
 * Creates new QRCamera from frontal camera
 * @example
 * const canvas = new QRCanvas();
 * const camera = frontalCamera();
 */
export async function frontalCamera(player: HTMLVideoElement): Promise<QRCamera>

Example directive is perfectly valid JS code, and has always been. However, JSR doesn't highlight it -- and even worse, doesn't even add line-breaks. JSR needs this:

@example
```js
const canvas = new QRCanvas();
const camera = frontalCamera();
```

It's unreasonable to require all jsdoc code example to be replaced by this flavored markdown just because you can't fix your code.