copy from https://github.com/GitbookIO/plugin-katex, but support inline formula.
Math typesetting using KaTex
Use it for your book, by adding to your book.json:
{
"plugins": ["katex"]
}
then run gitbook install.
Usage
Inline math: $\int_{-\infty}^\infty g(x) dx $
You need to put a space before $.
Block math:
$$ \int_{-\infty}^\infty g(x) dx $$
input $
The plugin uses $ to indicate inline formulas. If you want to only input a $, you can use \$``( in code mode),