feat(seo): enhancements for rich Google and LLM results

Add WebPage/CollectionPage schema, BreadcrumbList, and configurable llms.txt output for better rich results and AI crawling.

New `marketing.seo.llm` params added to `params.yaml` to config llm scraping prefs.

templates/documentation/config/_default/params.yaml

@@ -15,7 +15,7 @@ marketing:
     local_business_type: ''
     org_name: ''
     description: 'A highly-customizable Hugo documentation theme powered by Hugo Blox website builder.'
-    twitter: 'GetResearchDev'
+    twitter: 'BuildLore'
   analytics:
     google_analytics: ''
     google_tag_manager: ''