support math formulas

[juancarlosfarah]

Support mathematical equations like the following:

    \begin{matrix}
    1 & x & x^2 \\
    1 & y & y^2 \\
    1 & z & z^2 \\
    \end{matrix}

A \[ indicates the beginning of a block, while a \] indicates its end.

A \( indicates the beginning of an inline expression, while a \) indicates its end.

[juancarlosfarah]

We are going to go with Katex, which basically supports all of the things we need. This allows us to avoid MathJax craziness when working without their CDN.

Basically we will detect \[ and \( and we will parse the content inside using Katex. We will then render it inside a Quill div as readonly. This is a very flexible solution that will allow us to write math in the future too.

Tagging @ahgentil for awareness.