Fallback option to infer code languages from elements

[calvellido]

Given the way this web component will be used, where highlighters will be playing a role, and they add proper classes or attributes as part of their rendering, we could add an option where the code snippet language could be inferred from the element is none is set:

<div class="language-groovy highlighter-rouge">
(...)
</div>

<div class="language-kotlin highlighter-rouge">
(...)
</div>