Support for Equations in the Markdown Editor

Would be great to have support for equations in the markdown editor so that if I enter something like

$$
a^2 + b^2 = c^2
$$

I get a pretty formatted equation like:

I just tried this on the demo site:
https://cms-demo.netlify.com/#/collections/posts/entries/2018-4-18-post-number-10

And it does not currently format:

Is this a planned or current feature? If current how do you use it?

Cheers and Thanks
Dave