Document use of Greek letters, mathematical expressions and similar

[jpw]

Answer: UTF 8 everywhere, font choices, and MathJax

[RSeidelsohn]

Just we need to ensure that the fontsets used contain the necessary characters.

[efasel]

@moddular said in slack:

FWIW, in articles equations are usually stored as TeX in the A++. We use MathJax with our config https://github.com/springernature/mathjax-config to render the TeX in the article.