By enabling math in the config.toml, you can include mathematical expressions powered by $$\KaTeX$$ in your pages:
[Params]
...
math = true
...
This will be useful especially for pages with scientific contents.
For example, by writing
$$
-\frac{\hbar^2}{2m}\left(\nabla^2 + V(\boldsymbol{r}) \right)\phi(t,\boldsymbol{r}) = i\hbar \frac{\partial}{\partial t} \phi(t,\boldsymbol{r}),
$$
it will be rendered as
$$ -\frac{\hbar^2}{2m}\left(\nabla^2 + V(\boldsymbol{r}) \right)\phi(t,\boldsymbol{r}) = i\hbar \frac{\partial}{\partial t} \phi(t,\boldsymbol{r}) . $$
If you want to insert an equation inline, by writing $E=mc^2$, you get $E=mc^2$.
