MathJax support

[ggbetz]

When reconstructing technical arguments, it would nice to have the full set of mathemtical symbols and syntax available. Maybe this could be achieved through integrating MathJax in Argdown?

<Argument with Mathematical Notation>

(1) $\sum_i \frac{1}{p_i}>1$
(2) ...
----
(3) ...

[christianvoigt]

For mathematical symbols we already have the option to use custom shortcodes. You could for example define a :pi: shortcode. More complex formula will be a problem for the node labels in Viz.Js and Dagre.js, so I do not think that we can support it without a major effort.