Code blocks aren't scrollable on mobile

[swantzter]

Code blocks generated by rst seem to have. overflow:hidden, however in a demo with markdown it worked and had a nfie background colour. Without having looked I suspect one generates pre+code and the other one just generates one of them. If not cssable, this should be addressed here: https://github.com/swantzter/jekyll-rst/blob/master/rst2html5.py#L52