Docs style updates

[donjo]

To-do list, roughly in order of priority

Before Shipping

• remove container wrapper from footer or come up with a new class to wrap all the docs content instead of container so the content itself can sit closer to the navigation (right now container has custom margins and it is used in the footer as well as the docs content
• fix contrast issue on the global search box in the nav
• ensure color palette is accessible

Nice to have before shipping

• try styling the manual/tutorials/api reference in a way that highlights when you're browsing content in that section (currently does it if you are on the overview of tutorials and examples but would be nice to have that active state maintained if you are browsing any content in that section)

Later

• adjust icons placement/size so they are all visually similar and have the appropriate text baseline next to them
• replace logo with wordmark verison of logo that includes the word docs

[donjo]

am I supposed to commit this?