Math errors with newlines and standalone $'s

[danielwe]

• Newlines \\ within math environments are replaced by single backslashes:

$$
\begin{matrix}
  a & b \\
  c & d
\end{matrix}
$$

renders to

$$
\begin{matrix}
a & b \
c & d
\end{matrix}
$$

I.e., the substitutions \ -> <br> and \\ -> \ are performed even inside math environments, resulting in incorrect math expressions after MathJax processing.

• Dollar signs that are clearly not math environment delimiters are treated as such:

I earned $10 and spent $5.

10 and spent is processed as math by MathJax. (Note, for example, that pandoc defines rules for when a pair of dollar signs should be treated as a math environment, see https://pandoc.org/MANUAL.html#math).

One solution could be to use the markdown-it-mathjax plugin, which takes care of all of this. However, that appears to require enabling the '\\(','\\)' inline math delimiters, which were disabled in #14.