Where do I add extra packages from mathjax?

[damitr]

Hi,

I was able to successfully render mathjax on my github pages site by adding mathjax.html file _includes directory and then calling it in the default.html.

my mathjax.html files looks like this

<script type="text/x-mathjax-config">
MathJax.Hub.Config({
    TeX: {
      equationNumbers: {
        autoNumber: "AMS"
      }
    },
    tex2jax: {
    inlineMath: [ ['$','$'], ["\\(","\\)"] ],
    displayMath: [ ['$$', '$$'], ["\\[]","\\]"] ],
    processEscapes: true,
  }
});
MathJax.Hub.Register.MessageHook("Math Processing Error",function (message) {
	  alert("Math Processing Error: "+message[1]);
	});
MathJax.Hub.Register.MessageHook("TeX Jax - parse error",function (message) {
	  alert("Math Processing Error: "+message[1]);
	});
</script>
<script type="text/javascript" async
  src="https://cdn.mathjax.org/mathjax/latest/MathJax.js?config=TeX-MML-AM_CHTML">
</script>

Mathjax supports a few latex packages as well. They can be seen at
https://docs.mathjax.org/en/latest/input/tex/extensions/index.html

My question is where do I add this code to enable/load the physics package

window.MathJax = {
  loader: {load: ['[tex]/physics']},
  tex: {packages: {'[+]': ['physics']}}
};