Boostlook style updates

[rbbeeston]

There are a few minor tasks:

1. make number bullets back to normal
2. remove color from visited links
3. fix code italicized fonts
4. flashing in background of docs when changing pages (set standard background color)
5. square up code box, callout and table rectangles
6. get rid of code block headers
7. call out box text (not headers) not so bold
8. add noto sans mono italic
9. tighten up menu spacing
10. remove code block background styling inside of td's

[rbbeeston]

@vinniefalco tracking changes here

[rbbeeston]

Leaving open for the list of requirements, but may be handled by Metalab