Followup to Conditional HTML Styling
Follows #10250

For 0.17.1
- [x] Nicer table styling for the pydata.org website
- [x] Include a visual example in 0.17.1.rst
- [x] remove `doc/source/html-styling.html` and find a way to include `doc/source/html-styling.ipynb` in the doc build (should use `--template=basic`)
- [x] update `print_versions`
- [x] update `requirements_all.txt` to include jinja

For 0.18.0 / Future
- [x] sparsify MultiIndex repr (maybe push till 0.18)
- [ ] easy alignment styles #12144 
- [ ] Template modification: This is for things like wrapping base64 encoded values in `img` tags, urls, etc. flows into...
- [ ] Break the large template in `Styler.template` into smaller blocks. Let people extend that. We could (maybe) allow users to choose which template to use to render each column/cell with solving the template modification problem
- [ ] Truncated repr
- [ ] hook into `pd.options`, allow setting of default reprs with styles
- [ ] Refactor parts of `Styler` into a `BaseStyler`, maybe add a LaTeX styler (maybe deprecate / replace the `to_html` and `to_latex` methods; Jinja templates are much more pleasant to work with), xref #11700 
- [ ] Categoricals / Boolens  builtin stylings

will add more as we go.
