Syntax highlighting messed up in README

[mtfishman]

Unfortunately, syntax highlighting is messed up in the Github README. It looks like it doesn't recognize jldoctest, so doesn't do the highlighting it would do if julia is used next to the codeblock (one block of code is showing up correctly, but that is because I forgot to change it to be a doctest).

[mtfishman]

Perhaps we can just start linking people to the documentation page anyway, and just have a short description in the Github README section (we probably don't need these long examples there).