Render KaTex/MathJax from Markdown using Github Pages

Suppose I create a Github Pages repository github.com/user/user.github.io containing ./index.md with the following contents describing a mathematical expression:

---
title : math demo
author : user
---

# Github Pages Markdown + TeX Math Demo

$$ \vec{\text{F}} =q(\vec{\text{E}}\ + \vec{\text{v}}\times\vec{\text{B}}) $$

By default, it seems github pages hosts html rendered from the markdown source available at user.github.io, but it strangely seems to convert $$ $$ to \[ \] and preserves the math as plain text. Is there some way, maybe an option in _config.yml, to specify Github to use something like KaTeX or MathJax to properly render the equations when applicable.

I was able to render MathJax by placing the following lines after my YAML front matter in my markdown files:

<script src="https://polyfill.io/v3/polyfill.min.js?features=es6"></script>
<script id="MathJax-script" async src="https://cdn.jsdelivr.net/npm/mathjax@3/es5/tex-mml-chtml.js"></script>

This solution is okay but I was hoping there was a way I could apply this to all markdown as a repository default as well if there was a way to instead render with KaTeX. This might improve client side performance as would it be consistent with my markdown editor (VS Code + Markdown+Math) which can quickly render equations using KaTeX.