Render Hooks for Markdown Code Fences

Hi there,

According to this the only supported features are image, link and heading.

Is there any possible way to add Code Fences for this?

For context, we have the following documentation that we need to do custom processing and decorate the output HTML with more info:

```csharp {type="client" framework="dotnet"}
// Use "https" scheme if you've setup SSL.
var client = new Client("http", "127.0.0.1", 7350, "defaultkey");
```csharp {type="client" framework="unity"}
// Use "https" scheme if you've setup SSL.
var client = new Client("http", "127.0.0.1", 7350, "defaultkey");

We’ve so far used a shortcode to achieve this functionality but it’s not very pleasant and would like to see if it’s possible just to tag the extra attributes as needed as part of the regular markdown syntax?

I’ve just seen this: Add some hook API for code blocks · Issue #8520 · gohugoio/hugo · GitHub