Produces a custom output format function in the style of Edward Tufte's handouts. This essentially recreates the tufte-handout latex document class using bootstrap. Main features are plot hooks that put figures in the margin (marginfigure = TRUE), creates full-width figures (fig.star = TRUE), and allows "sidenotes". To create a sidenote, some raw html is required. Usage is <aside> Content </aside>. See the package vignette for more details.