LaTeX support comes from https://github.com/Wyatt915/treeblood through https://github.com/Wyatt915/goldmark-treeblood.
I've gone through the Treeblood codebase (in its current state) and added every MathML attribute and element that it uses to the sanitizer. This means that there's a chance that Treeblood uses new elements/attributes in the future that aren't included in the current list, but as of Treeblood v0.1.15 I'm fairly sure everything is there.
goldmark-treeblood also caused the Goldmark version to be updated to v1.7.12, where it was previously on v1.4.15. I'm not sure if there was a specific reason why v1.4 was being used, or if it simply hadn't been updated, but I've updated that, and left all other dependencies untouched.
looks pretty good! few comments: