MathJax not rendered in blog posts

**Describe the issue**
On pages such as
- https://fluxml.ai/blogposts/2019-03-05-dp-vs-rl/
- https://fluxml.ai/blogposts/2019-02-07-what-is-differentiable-programming/

equations are not rendered.

**Screenshots**
For example:
<img width="701" alt="Screenshot 2024-11-25 at 10 12 56" src="https://github.com/user-attachments/assets/f784cf54-fe0f-4c9c-aeed-d55e41efa9b3">
