reformat boostlook for the new site design

[rbbeeston]

This involves a couple of different steps:

1. Create a boostlook2.css as a copy of the original
2. See if there is anything that can be done to simplify the current css.
3. Update boostlook to match the figma views provided by Metalab.

[julioest]

Progress update — I'm working on this in boostorg/boostlook#173.

So far I've:

• Renamed CSS color primitives to match the Figma design system (neutral → primary, blue → secondary)
• Cleaned up ~30 unused color variables and legacy syntax palette
• Added new tokens to match Figma specs (surface/page, body text color)

Components touched so far: variables, themes, typography, links, code blocks, components, tables/images, layout, Asciidoctor styles, Antora styles, and Quickbook styles.

Next up is auditing the rest of the semantic tokens (buttons, icons, navigation, strokes, surfaces, text) against Figma.

Preview site: https://boostlook-v3.netlify.app/

This preview site is a landing page that includes several things:

• Style Guide
• Capy library
• CharConv library
• Site Docs

Note: these are "standalone" docs, so we won't know how they'll really render until they're used in the Django website.