Pretty-jupyter

What's Changed
* 32 remove not used imports by JanPalasek in https://github.com/JanPalasek/pretty-jupyter/pull/33
* Added example and better support for plotly.

- Added selenium tests for report outputs.
- Improved handling of obscure markdown document structures.
- Fixed math mode for older versions of nbconvert. (< 6.1)
- Improved tables flexibility: automatic styling by applying css classes can be now disabled with a token.
- Added %%jmd alternative for %%jinja markdown.

- Added class to avoid global JS changes to the table: `pj-tab-ignore`.
- Improved behaviour for erroneous tabset specifications.
- Fixed math mode for older versions (6.0 nbconvert).
- Added shortcut for jinja markdown (`%%jmd`).

- Improved styling.

- Fixed an issue where math mode didn't work in tandem with tabsets.
- Lightened the repo, moved the big files from the repo to specific examples.

What's Changed
* 20 minimum version for nbconvert by JanPalasek in https://github.com/JanPalasek/pretty-jupyter/pull/21


**Full Changelog**: https://github.com/JanPalasek/pretty-jupyter/compare/1.1...1.2.0