Rebrand and clean up Sphinx CSS

[nicolaskruchten]

Two things:

1. We need to rebrand https://plotly.com/python-api-reference/ with the new colors (let's leave the fonts alone for now)
2. We need to tweak the CSS a bit to better-format the markup that comes out of Sphinx

Re the latter, here's what comes to mind:

• reformat blockquote so it doesn't look like a quote and doesn't make the text bigger
• reformat dt/dd so that the terms aren't bold and the definitions are a bit indented
• maybe add a bit of whitespace above/below li to make things breathe a bit?

[nicolaskruchten]

In terms of how: cd doc/apidoc && make html to build it... Hopefully all this stuff is just a set of "overrides" in https://github.com/plotly/plotly.py/blob/master/doc/apidoc/_static/plotly-style.css

[nicolaskruchten]

Ah, small and annoying wrinkle: it's hard/impossible to correctly build the entire docs on MacOS due to its case-insensitive filesystem.

Probably best to use the inspector stylesheet or something to do this :(

[nicolaskruchten]

While trying to see how easy this inspector-stylesheet approach is to use, I basically ended up implementing most of the points in part 2 here... sorry! a78442b

[gvwilson]

@LiamConnors is this still an open concern?

[LiamConnors]

the page looks okay to me. I'm not certain on the reasons for the original issue and what was worked on. Closing it out