Show HN: MathQuill, my open source JS formula editor

Thanks! Happy to answer any questions here or in our Slack (http://slackin.mathquill.com)

Lots, the biggest probably being environments like matrices (\begin{pmatrix}...\end{pmatrix}) and piece-wise functions (\begin{cases}...\end{cases}).

Lots of work to be done! And we love new contributors :)