Add support for ipynb files

[laurentperrinet]

What file type Jupyter notebooks, a.k.a. ipynb are pages containing code written in different langugaes: julia, python, R, ... and widely used in data analysis, science, finance, ... These get rendered when on a github page (e.g. https://github.com/odewahn/ipynb-examples/blob/master/Part%201%20-%20Running%20Code.ipynb ).

What application is using it Many applications in the jupyter ecosystem use notebooks: https://jupyter.org/ , https://voila.readthedocs.io , ...

Sample file ipynb sample file

[Spartachetto]

In addition to the Jupyter notebooks, I'd like to remember an old request to support the Rmarkdown files. Those are markdown files used by R that include code sections.

Here is the feature request: https://github.com/icewind1991/files_markdown/issues/38