dynamically render Latex expressions in web preview using MathJax before rendering as PNG

[bhpayne]

As identified in a previously resolved bug https://github.com/allofphysicsgraph/proofofconcept/issues/229 , the ability to preview Latex prior to rendering as a PNG would help decrease user input errors. Relying on the user to manually select "check input" is inferior to dynamically rendering Latex using Mathjax in the web interface.

[bhpayne]

Examples:

• https://www.mathjax.org/#demo
• http://bandicoot.maths.adelaide.edu.au/MathJax/test/sample-dynamic-2.html
• https://www.tuhh.de/MathJax/test/sample-dynamic-2.html

Explanation

• https://docs.mathjax.org/en/v2.7-latest/advanced/dynamic.html
• https://stackoverflow.com/a/62246086/1164295