Configuring Mathjax

Mathjax is mildly straightforward, thanks to its instructions.

The `tags: 'ams'` is responsible for automatic equation numbering.

I am also trying to use $ for inline math (TeX delimiters which I prefer).

I've also added a few custom macros, some borrowed from Springer's style classes, others just shorthand. They're implemented using mathjax's configmacros, which may turn out to be a terrible idea...

If (somehow) I botch things later on, and need to backtrack to start over with the mathjax configuration, then this is what it looks like:

<script>
MathJax = {
  loader: {
    load: ['[tex]/ams']
  },
  tex: { 
    macros: {
      RR: "\\mathbb{R}",
      D: "\\mathrm{d}",
      E: "\\mathrm{e}",
      I: "\\mathrm{i}"
    },
    tags: 'ams',
    inlineMath: [['$', '$'], ['\\(', '\\)']],
    packages: {'[+]': ['ams']},
    autoload: {color: []}
  }
};
</script>
<script type="text/javascript" id="MathJax-script" async
  src="https://cdn.jsdelivr.net/npm/mathjax@3.0.0/es5/tex-chtml.js">
</script>