Adds mathjax

Description

Mathjax was added to render complex formulas correctly. It will render only formulas within the html class mathjax-render.

It is used in the ecological_assesment documentation in this MR

Screenshots/Logs

Attach screenshots or log outputs if applicable.

Testing Instructions

1. Compare screenshots with old documentation of ecolgical_assessment (in Basic Concepts / Dallara / General Principles)
2. Use mkdocs to build new version
3. Check whether formulas are correct rendered

Developer Checklist

• Code has been tested locally and/or in pipeline.
• (if applicable) documentation updated.
• (if applicable) impact of new dependencies reviewed and included in project.
• Merge conflicts resolved with the target branch.