Introducing Pesto, a mobile first, retina-ready, clean custom style

New Marked custom style forked from *Kult* by [Peter Sziebig (@bigpe)](https://twitter.com/bigpe). Currently in use to style [my résumé](http://www.acusti.ca/resume/). See [its repo](https://github.com/acusti/Custom-Marked-Styles) for details.