Global mathjax parameter is not working

[Abel Soares Siqueira]

Describe the bug
Setting mathjax globally doesn't work.

To Reproduce
Steps to reproduce the behavior:

1. Go to 'paramsinconfig.yaml`
2. Add mathjax: true
3. And check that it doesn't enable mathjax

Expected behavior
I expect the same result as if I set it on the page frontmatter.

Screenshots
If applicable, add screenshots to help explain your problem.

Desktop (please complete the following information):

• OS: Linux
• Browser: Opera
• Version 104

Additional context