TeX support

You can write math by TeX. With $$ and $$$, write some equations.

# TeX support
$$$ 1 + \frac{q^2}{(1-q)}+\frac{q^6}{(1-q)(1-q^2)}+\cdots = \prod_{j=0}^{\infty}\frac{1}{(1-q^{5j+2})(1-q^{5j+3})}, \quad\quad \text{for }\lvert q\rvert<1. $$$

## inline math
This $$\begin{Bmatrix}
   a & b \\
   c & d
\end{Bmatrix}$$ is a matrix

Refer https://khan.github.io/KaTeX/function-support.html for more information about what functions you can write.