Syntax highlighting in Go

[lukewhrit]

By dropping highlight.js and converting our syntax highlighter to be pure Go and done completely on the server-side we can ensure a fully featured experience for users that chose to disable JavaScript. 100% removing JavaScript from the site will ensure our website is faster and less vulnerable to bugs.

We can use Alec Thomas' Chroma library for this. With Chroma, we can automatically detect the languages but we should also add a way to override the language.