upgrade to MathJax 3

MathJax 2 is rendering some stupid font in WebKitGTK.

assets/js/mathjax-config.js

@@ -1,10 +1,19 @@
 window.MathJax = {
-  CommonHTML: {linebreaks: {automatic: true}},
-  tex2jax: {
+  tex: {
     inlineMath: [['$', '$'], ['\\(', '\\)']],
     displayMath: [['$$', '$$'], ['\\[', '\\]']],
-    processEscapes: false
+    processEscapes: false,
+    autoload: {
+      color: [],
+      colorV2: ['color']
+    },
+    packages: {'[+]': ['noerrors']}
   },
-  TeX: {noUndefined: {attributes: {mathcolor: 'red', mathbackground: '#FFEEEE', mathsize: '90%'}}},
-  messageStyle: 'none'
+  options: {
+    ignoreHtmlClass: 'tex2jax_ignore',
+    processHtmlClass: 'tex2jax_process'
+  },
+  loader: {
+    load: ['[tex]/noerrors']
+  }
 };

data/assets.toml

@@ -16,9 +16,8 @@
   sri = "sha256-aYTdUrn6Ow1DDgh5JTc3aDGnnju48y/1c8s1dgkYPQ8="
   url = "https://cdnjs.cloudflare.com/ajax/libs/highlight.js/%s/highlight.min.js"
 [js.mathJax]
-  version = "2.7.4"
-  sri = "sha256-GhM+5JHb6QUzOQPXSJLEWP7R73CbkisjzK5Eyij4U9w="
-  url = "https://cdnjs.cloudflare.com/ajax/libs/mathjax/%s/MathJax.js?config=TeX-AMS_CHTML-full"
+  version = "3"
+  url = "https://cdn.jsdelivr.net/npm/mathjax@%s/es5/tex-chtml.js"
 [js.isotope]
   version = "3.0.6"
   sri = "sha256-CBrpuqrMhXwcLLUd5tvQ4euBHCdh7wGlDfNz8vbu/iI="