Cljdoc now renders https://docs.github.com/en/get-started/writing-on-github/getting-started-with-writing-and-formatting-on-github/basic-writing-and-formatting-syntax#alerts. Styling is the same as for adoc admonitions, https://cljdoc.org/d/org.cljdoc/cljdoc-exerciser/1.0.108/doc/document-tests/commonmark-features#alerts.