configure arithmatex for v3

as documented in https://squidfunk.github.io/mkdocs-material/setup/extensions/python-markdown-extensions/#arithmatex

Author: PhilippSalvisberg

docs/javascripts/mathjax.js

@@ -0,0 +1,17 @@
+window.MathJax = {
+    tex: {
+      inlineMath: [["\\(", "\\)"]],
+      displayMath: [["\\[", "\\]"]],
+      processEscapes: true,
+      processEnvironments: true
+    },
+    options: {
+      ignoreHtmlClass: ".*|",
+      processHtmlClass: "arithmatex"
+    }
+  };
+  
+  document$.subscribe(() => {
+    MathJax.typesetPromise()
+  })
+  

mkdocs.yml

@@ -18,17 +18,21 @@ theme:
     accent: 'red'
 
 extra_css:
-  - 'stylesheets/extra.css'
+  - stylesheets/extra.css
 extra_javascript:
-  - 'https://cdnjs.cloudflare.com/ajax/libs/mathjax/2.7.0/MathJax.js?config=TeX-MML-AM_CHTML'
+  - javascripts/mathjax.js
+  - https://polyfill.io/v3/polyfill.min.js?features=es6
+  - https://cdn.jsdelivr.net/npm/mathjax@3/es5/tex-mml-chtml.js
+
 markdown_extensions:
   - admonition
   - pymdownx.highlight:
       linenums: true
       linenums_style: table
   - pymdownx.superfences
   - pymdownx.inlinehilite
-  - pymdownx.arithmatex
+  - pymdownx.arithmatex:
+      generic: true
   - footnotes
 
 extra: