Breadcrumbs and header update Fixes #272

[knice]

What does this do/fix?

New

• Move breadcrumbs to a permanent location beneath the main navigation in all page templates
• Adjust styles for breadcrumbs (slightly larger font, a11y-appropriate color, and link colors)
• Last crumb is now the unlinked title of the current page
• Remove the "with breadcrumbs" no title template
• Modify space between crumbs and page title in both templates

Changes

• Small typographic adjustment to the quote block styles
• Soften the drop shadow beneath main nav
• Balance typography of all headings with text-wrap: balance
• Remove unused serif font declaration from the theme
• Remove the unused logo switch function (deprecated when we added Truss header to the theme)

Links to relevant issues

• Issue 272

Tests

• Does your site pick up the changes to the "page-no-title" template? Breadcrumbs should appear there
• Do all of the pages on your site display the crumbs in their new location?
• What happens on a page that was previously using the "page-no-title-with-breadcrumbs" template? That template is deleted in this PR

[Herm71]

Works great!