Update ReadTheDocs to use latest MkDocs #554
@ericholscher Thanks! Can we define what blocks are needed from themes so they work on ReadTheDocs? See #355 and readthedocs/readthedocs.org#978 (comment). I want to add blocks and reduce the duplication of the theme that you guys have - this should then reduce the risk of us breaking something if you only inject into small defined areas. We can then document that and add support in other themes.