Hello.

I am using a HTML documentation page by an external service which renders JSON snippets within an HTML page.
The HTML source code looks like this:

<pre>{
    "product-link": "https://example.com/product-link",
    "teaser_image": "https://example.com/teaser-image",
    "product_image_first": "https://example.com/product-image-first",
    "headline": "Example headline",
}</pre>

The JSON block renders without syntax highlighting.
Since I am not in control of the external service I would like to apply syntax highlighting to the JSON snippet via user script.

Can someone please give me a direction on how I could do that?
Thank you, John