Integrate with MathJax 3

Patch to do what you are describing.

For version 3 to work, I found I could use either of these CDNs:

• https://cdn.jsdelivr.net/npm/mathjax@3/es5/tex-mml-chtml.js
• https://cdn.jsdelivr.net/npm/mathjax@3.2.2/es5/tex-mml-chtml.min.js

And I needed to change the "Custom configuration" to:

{"tex": {"inlineMath": [["$", "$"], ["\\(", "\\)"]]}}

I applied in comment #4 and it works well.

My config is the same as comment #7.

Should we update the patch to include that as the default config?