Quantecon-book-theme

This release includes a few refactoring, enhancements, and features:

- Upgraded to mathjax v3 from v2.
- Making interact feature of ipywidgets work with mathjax.
- Using web-compile https://github.com/executablebooks/web-compile to minify and hash css, js files. And create theme.conf file.
- Added tox.
- Reshuffling js files, and making tippy and feather work with it.
- Style changes in right navigation menu.
- Added UI to handle multiple launch buttons.
- Adding book and pdf download buttons.

Right sidebar navigation fix with numbering included.

Refactored code for `pydata-sphinx-theme~=0.6.0`

This release contains fixes for Mathjax fonts, some fixes in test regression file and pre-commit, plus has the styling to match the math content table to that of a sphinx site.

This release centers the code output figures and images included in the markdown.

This release has the following fixes/improvements:

1) anchor links behind hidden toolbars.
2) removing padding on math focus.
3) math size in headings.