Replace MathJax integration with official Just The Docs suggestion

_config.yml

@@ -30,6 +30,8 @@ liquid:
   #strict_variables: true # commented out because it isn't supported by just-the-docs
   strict_filters: true
 
+math: mathjax
+
 defaults:
   - scope:
       path: ""

_includes/head_custom.html

@@ -9,4 +9,11 @@
 
 <meta name="Keywords" content="GAP,group theory,computational group theory,algebra,computational algebra,computational discrete algebra,mathematical computation" />
 
+{% assign math = page.math | default: layout.math | default: site.math %}
+
+{% case math %}
+  {% when "mathjax" %}
+    {% include mathjax.html %}
+{% endcase %}
+
 <title>{{ page.title }}</title>

_includes/mathjax.html

@@ -0,0 +1,9 @@
+<!-- Automatically display code inside script tags with type=math/tex using MathJax -->
+<script type="text/javascript" defer
+  src="{{ site.baseurl }}/assets/js/mathjax-script-type.js">
+</script>
+
+<!-- Copied from https://docs.mathjax.org/en/latest/web/components/combined.html -->
+<script type="text/javascript" id="MathJax-script" defer
+  src="https://cdn.jsdelivr.net/npm/mathjax@3/es5/tex-svg.js">
+</script>

_layouts/default_with_title.html

@@ -2,19 +2,4 @@
 layout: default
 ---
 <h2>{{ page.title }}</h2>
-<!-- add script to allow latex code to be displayed -->
-<script>
-    MathJax = {
-      tex: {
-        inlineMath: [ ['$', '$'], ['\\(', '\\)'] ]
-      },
-      svg: {
-        fontCache: 'global'
-      }
-    };
-    </script>
-    <script
-      type="text/javascript" id="MathJax-script" async
-      src="https://cdn.jsdelivr.net/npm/mathjax@3/es5/tex-svg.js">
-    </script>
 {{ content }}

_layouts/mathjax.html

@@ -0,0 +1,12 @@
+---
+layout: default
+math: mathjax
+---
+<div style="display: none">
+  \(
+  <!-- optional definitions using \newcommand, etc. 
+       see https://docs.mathjax.org/en/latest/input/tex/macros.html -->
+  \)
+</div>
+
+{{ content }}

assets/js/mathjax-script-type.js

@@ -0,0 +1,25 @@
+// Copied from https://docs.mathjax.org/en/latest/upgrading/v2.html#changes-in-the-mathjax-api
+MathJax = {
+      tex: {
+        inlineMath: [ ['$', '$'], ['\\(', '\\)'] ]
+      },
+      svg: {
+        fontCache: 'global'
+      },
+
+  options: {
+    renderActions: {
+      findScript: [10, function (doc) {
+        for (const node of document.querySelectorAll('script[type^="math/tex"]')) {
+          const display = !!node.type.match(/; *mode=display/);
+          const math = new doc.options.MathItem(node.textContent, doc.inputJax[0], display);
+          const text = document.createTextNode('');
+          node.parentNode.replaceChild(text, node);
+          math.start = {node: text, delim: '', n: 0};
+          math.end = {node: text, delim: '', n: 0};
+          doc.math.push(math);
+        }
+      }, '']
+    }
+  }
+};