Switch to JavaScript syntax highlighter

doc/fmt.js

@@ -0,0 +1,3 @@
+document$.subscribe(() => {
+  hljs.highlightAll()
+})

mkdocs.yml

@@ -13,17 +13,24 @@ theme:
     - navigation.tabs
     - toc.integrate
 
+extra_javascript:
+  - https://cdnjs.cloudflare.com/ajax/libs/highlight.js/10.7.2/highlight.min.js
+  - fmt.js
+
 extra_css:
+  - https://cdnjs.cloudflare.com/ajax/libs/highlight.js/10.7.2/styles/default.min.css
   - fmt.css
 
 markdown_extensions:
   - pymdownx.highlight:
+      # Use JavaScript syntax highlighter instead of Pygments because it
+      # automatically applies to code blocks extracted through Doxygen.
+      use_pygments: false
       anchor_linenums: true
       line_spans: __span
       pygments_lang_class: true
   - pymdownx.inlinehilite
   - pymdownx.snippets
-  - pymdownx.superfences
 
 plugins:
   - mkdocstrings: