Allow custom admonition styling for Caution GitHub Alerts

[cdwilson]

It looks like there is special handling for Caution GitHub Alerts that styles them as Danger and prevents styling them with custom CSS.

For example, I tried adding the following CSS to style Caution and Important GitHub Alerts:

:root {
  --md-admonition-icon--important: url('data:image/svg+xml;charset=utf-8,<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 16 16"><path d="M 1.75,1.5 A 0.25,0.25 0 0 0 1.5,1.75 v 9.5 c 0,0.138 0.1120001,0.25 0.25,0.25 h 2 a 0.75,0.75 0 0 1 0.75,0.75 v 2.189453 l 2.7207031,-2.71875 A 0.749,0.749 0 0 1 7.75,11.5 h 6.5 A 0.25,0.25 0 0 0 14.5,11.25 V 1.75 A 0.25,0.25 0 0 0 14.25,1.5 Z M 7.8339844,3.0195313 A 0.75,0.75 0 0 1 8.75,3.75 v 2.5 a 0.75,0.75 0 0 1 -1.5,0 V 3.75 A 0.75,0.75 0 0 1 7.8339844,3.0195313 Z M 8,8 A 1,1 0 0 1 9,9 1,1 0 0 1 7,9 1,1 0 0 1 8,8 Z"/></svg>');
  --md-admonition-icon--caution: url('data:image/svg+xml;charset=utf-8,<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 16 16"><path d="M 5.3105469,1.5 1.5,5.3105469 V 10.689453 L 5.3105469,14.5 H 10.689453 L 14.5,10.689453 V 5.3105469 L 10.689453,1.5 Z M 8,4 a 0.75,0.75 0 0 1 0.75,0.75 v 3.5 a 0.75,0.75 0 0 1 -1.5,0 V 4.75 A 0.75,0.75 0 0 1 8,4 Z m 0,6 a 1,1 0 0 1 0,2 1,1 0 0 1 0,-2 z"/></svg>');

}

.md-typeset .admonition.important,
.md-typeset details.important {
  border-color: #7c4dff;
}

.md-typeset .important>.admonition-title,
.md-typeset .important>summary {
  background-color: #7c4dff1a;
}

.md-typeset .important>.admonition-title::before,
.md-typeset .important>summary::before {
  background-color: #7c4dff;
  -webkit-mask-image: var(--md-admonition-icon--important);
  mask-image: var(--md-admonition-icon--important);
}

.md-typeset .admonition.caution,
.md-typeset details.caution {
  border-color: #ff1744;
}

.md-typeset .caution>.admonition-title,
.md-typeset .caution>summary {
  background-color: #ff17441a;
}

.md-typeset .caution>.admonition-title::before,
.md-typeset .caution>summary::before {
  background-color: #ff1744;
  -webkit-mask-image: var(--md-admonition-icon--caution);
  mask-image: var(--md-admonition-icon--caution);
}

Here is the result when - github-callouts is enabled (Important is styled with custom CSS, but Caution is not using custom CSS):

However, if I remove - github-callouts and use - markdown_gfm_admonition (from markdown-gfm-admonition extension) instead, both Important and Caution are styled using the custom CSS:

Would it be possible to have an option to disable the special handling of the Caution Alert so that it can be styled via custom CSS?