[A11Y] WCAG 3.2.3 Consistent navigation: Breadcrumbs don't show on all pages

[jeff-horton-ho-sas]

Describe the accessibility issue
To meet WCAG 3.2.3 Consistent navigation - breadcrumbs don't show on pages excluded from 11ty collections

To Reproduce
Steps to reproduce the behavior:

1. Go to any of
   • http://localhost:8080/about/
   • http://localhost:8080/tags/
   • http://localhost:8080/tags/accessibility/ (or any other tag page)
   • http://localhost:8080/cookies/
   • http://localhost:8080/accessibility-statement/
2. The page does not show breadcrumbs

Expected behavior
For most of these pages a breadcrumb to the home page should show, for the tags it should show Home > Tags

Screenshots
Expected (example is a standard)

Actual (e.g a tag page)

Additional context
This looks to be due to the automated navigation via the eleventy-navigation plugin relying on the page being in the all documents collection to find it.

• Now that we have specific collections for each of principles, standards, and patterns we may be able to remove excludeFromEleventyCollections: true for these pages and it just works. If not add configutation using explicit setting of eleventyNavigation.key and .parent won't error due to the page not being in a collection.
• Alternatively we need to be able to provide manual breadcrumbs for a page via frontmatter, and add this for all pages excluded from collections.