markup/goldmark: Improve link and image render hook "always" enablement option

[jmooring]

Low priority.

In 84b3172 we changed embedded link and image render hook enablement from booleans to enums. When set to "always" we override custom hooks with the names "render-link.html" and "render-image.html". This is sufficient for (I would guess) 95% of sites, if not more.

However, the override logic does not work for custom hook template names with higher specificity such as:

• render-image.html.html
• render-image.en.html
• render-image.en.html.html
• and maybe others that I'm not thinking of at the moment.

I'm not sure we should even do something about this, but wanted it logged.

[bep]

I'm not sure we should even do something about this, but wanted it logged.

I'm not sure about this myself, either. I think this gets easier to reason about with e.g. render-image.json. I don't think we could ever consider fall back to the default render hook in that situation.

[jmooring]

Agreed. If we decide to do this, I think the match should be against the base name (e.g., render-image) and the output format (e.g., html). I logged this primarily to prevent theme authors from overriding the override; the site author should have authoritative control.