Syntax highlighting (Font and background colors) #40
Description
Looking at the English version of ThinkJulia I see that the background of the code blocks is grey, and the REPL code syntax is highlighted (via Pygments). The Spanish version at least has the grey background for the code and REPL blocks, though it also could be improved to get the syntax highlighting.
Looking at a recent version of the PTBR version such as the detalhes branch I do not see either the grey background or the syntax highlighting. I do not know how to fix this, though I guess it's something to do with Pygments. Maybe the pygments-julia repo will help?