- Add styling for active TOC item
- Add sidenav styles
- Change header tags to divs from index marketing page to remove anchors
- Fix use of card mixin and create separate card-docs class
- Add marketing styling
- Topnav styling when on home landing page
- Remove hamburger menu on home page
- Add fully rounded border to top nav toolbar search input
- Add mobile styles
- Add title banner to other marketing pages
Because:
1. `docs` feels like a "top level" page, similar to `features`, `resources`, `events` etc.
2. This enables the ServiceWorker to pre-fetch/cache the document (similar to what happens with all
other direct children of `content/docs/`), without the need for special-casing it in
`ngsw-manifest.json`.