update math support

Author: xnzone

layouts/partials/head.html

@@ -19,3 +19,5 @@
   {{ $js := slice $fusejs $search | resources.Concat "js/bundle.js" | resources.Fingerprint "sha512" }}
   <script defer type="text/javascript" src="{{ $js.Permalink }}" integrity="{{ $js.Data.Integrity }}"></script>
 {{- end }}
+
+{{ partial "mathjax.html" . }}

layouts/partials/math.html

@@ -0,0 +1,22 @@
+{{ if .Params.math }}
+<script>
+  MathJax = {
+    tex: {
+      inlineMath: [["$", "$"]],
+    },
+    displayMath: [
+      ["$$", "$$"],
+      ["\[\[", "\]\]"],
+    ],
+    svg: {
+      fontCache: "global",
+    },
+  };
+</script>
+<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>
+{{ end }}