katex-header.html

<link rel="stylesheet" href="https://cdn.jsdelivr.net/npm/katex@0.11.1/dist/katex.min.css" integrity="sha384-zB1R0rpPzHqg7Kpt0Aljp8JPLqbXI3bhnPWROx27a9N0Ll6ZP/+DiW/UqRcLbRjq" crossorigin="anonymous">
<script defer src="https://cdn.jsdelivr.net/npm/katex@0.11.1/dist/katex.min.js" integrity="sha384-y23I5Q6l+B6vatafAwxRu/0oK/79VlbSz7Q9aiSZUvyWYIYsd+qj+o24G5ZU2zJz" crossorigin="anonymous"></script>
<script defer src="https://cdn.jsdelivr.net/npm/katex@0.11.1/dist/contrib/auto-render.min.js" integrity="sha384-kWPLUVMOks5AQFrykwIup5lo0m3iMkkHrD0uJ4H5cjeGihAutqP0yW0J6dpFiVkI" crossorigin="anonymous"
        onload="renderMathInElement(document.body);">
</script>
<script>
    document.addEventListener("DOMContentLoaded", function() {
        renderMathInElement(document.body, {
            delimiters: [
                {left: "$$", right: "$$", display: true},
                {left: "\\(", right: "\\)", display: false},
                {left: "$", right: "$", display: false},
                {left: "\\[", right: "\\]", display: true}
            ]
        });
    });
</script>