Add MathJax rendering to the markdown viewer

**is your feature request related to a problem? Please describe.**
I use copyparty as a way to render my handwritten notes so that I can search them. Alot of my notes involve writing math and using [Mathjax](https://www.mathjax.org/) to format it all

**Describe the idea / solution you'd like**
A plugin to add mathjax rendering

This also may be useful to those who are using copyparty as a way to host the content of an obsidian vault