Merge LaTeX support from mathstodon

[attilakinali]

Pitch

Christian over at mathstodon (@christianp@mathstodon.xyz) added LaTeX support for mastodon, which allows proper rendering of formulas through mathjax, which can be found in his mastodon fork.

Would it be possible to integrate these changes into mastodon, so that all instances would correctly render LaTeX formulas without the need of running an unofficial fork?

Motivation

This would make discussing technical topics in physics and engineering, where formulas are common more accessible to a broader audience. Especially when discussing with lay-people, having a short formula makes things easier to convey. Unfortunately, if their instance doesn't use Christian's fork, they will get raw LaTeX code, which is just gibberish for mere mortals.

[nightpool]

dupe of #19806