Print out code and outputs rather than json format of ipynb files

[mogwai]

sublimehq/Packages#1741

This could be more useful to quickly inspect what's in a file vs the json version perhaps by default this could be disabled

[keith-hall]

Thanks for the suggestion. I feel this isn't something that would fit in the bat codebase directly, but would be solved by #2191 if someone wrote a pre-processor (or if there already exists such a thing) for it