Add BreadcrumbList schema data

[johnfraney]

Add breadcrumb structured data so it's visible in search results.

References:

• https://developers.google.com/search/docs/appearance/structured-data/breadcrumb#json-ld
• https://schema.org/BreadcrumbList

Example:

<script type="application/ld+json">
{
 "@context": "https://schema.org",
 "@type": "BreadcrumbList",
 "itemListElement":
 [
  {
   "@type": "ListItem",
   "position": 1,
   "item":
   {
    "@id": "https://example.com/dresses",
    "name": "Dresses"
    }
  },
  {
   "@type": "ListItem",
    "position": 2,
    "item":
   {
     "@id": "https://example.com/dresses/real",
     "name": "Real Dresses"
   }
  }
 ]
}
</script>