Netlify: Add MathJax to the Content-Security-Policy

netlify.toml

@@ -26,7 +26,8 @@
     # also specified inline, and unsafe inline JS script blocks are allowed
     # because it's needed for RTD theme navigation and the search function:
     # https://github.com/readthedocs/sphinx_rtd_theme/issues/817
-    Content-Security-Policy = "default-src 'self'; style-src 'self' 'unsafe-inline'; script-src 'self' 'unsafe-inline'"
+    # We also allow loading MathJax, which is needed to render math formulas.
+    Content-Security-Policy = "default-src 'self'; style-src 'self' 'unsafe-inline'; script-src 'self' https://cdn.jsdelivr.net/npm/mathjax@3/ 'unsafe-inline'; font-src 'self' https://cdn.jsdelivr.net/npm/mathjax@3/"
 
     # Disable all browser features that we don't need. Unfortunately
     # there is no way to specify a default for all directives yet, so