feat(aio): marketing design refresh

- 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

aio/e2e/app.e2e-spec.ts

@@ -22,7 +22,7 @@ describe('site App', function() {
 
     // navigate to a different page
     page.getLink('features').click();
-    expect(page.getDocViewerText()).toMatch(/Features/i);
+    expect(page.getDocViewerText()).toMatch(/Progressive web apps/i);
 
     // Show the menu
     page.docsMenuLink.click();