DOC: Enhance docs for Styler: details and high level.

[attack68]

Location of the documentation

ecosystem, + user_guide/index.rst + style.ipynb + visualization.rst
possibly others.

Documentation problem and proposed changes.

High Level

Scientific data visualization is not just restricted to charting. Tabular data visualization is important and Styler has some really good features for dealing with this - albeit Styler is not a recognised scientific term.

Currently the User Guide has left navigation links Visualization and Styling, and I would like to rename them Chart Visualization and Table Visualization and put them next to each other in the list. Also with some cross-refs.
The Api page has a Style navigation link which is probably best left as is due to API naming.

Low Level

a) I will revisit the style.ipynb page and update it with many of the new features, and possibly provide more of a continuous real-case example, rather than using numpy.random repeatedly to demonstrate the features. This isn't completely necessary but maybe works well.

b) I will revisit the function doc strings to ensure consistency on the API page (there is some inconsistency currently) and add examples where missing to the API page.

If you feel this is warranted or have any comments on the items please share before I get started.

[jreback]

sounds reasonable

note that we can do redirects for new page names (see conf.py)