Add notes on Markdown Extension defaults

[ChrisMayfield]

Description

On the "Authoring > Math" page, the documentation says (in two places) to add these lines to the toml file:

[project.markdown_extensions.pymdownx.arithmatex]
generic = true

However, doing so breaks the build. The attr_list extension stops working, the code fences stop rendering, and perhaps other extensions are affected.

I learned via Discord (12/5/25, 11:12 AM) that these lines are already part of the default configuration. Does including those lines in the toml somehow conflict with the defaults?

Related links

• https://zensical.org/docs/authoring/math/
• https://zensical.org/docs/setup/extensions/python-markdown-extensions/

Proposed change

Either remove the these lines (multiple instances) from the documentation or fix a potential bug when the settings are loaded.

Before submitting

• I have read and followed the documentation issue guidelines.
• I have attached the links to the affected sections of the documentation

[squidfunk]

Thanks for reporting. We understand this is a common confusion, and will fix this once we work on configuration and presets. We need to document the settings for users that change Markdown Extensions, so we can't remove them, but we might add a note that if you add those lines, you will override the default configuration in the time being.

@alexvoss, hope it's okay I'm assigning this to you.

[squidfunk]

Fixed in 91b5c32.