Correct Edit on GitHub button and breadcrumbs

[nate-double-u]

The CNI section has the "Edit on GitHub" button and breadcrumbs nav present on most of its pages, but it is entirely missing on the pages in the Plugins section.

[nate-double-u]

For example:

Present here: https://www.cni.dev/cni/dco/ but not here: https://www.cni.dev/cni/spec/ or here: https://www.cni.dev/plugins/pkg/ns/

It isn't present in any of the Plugins pages, and is present in most (but not all) of the CNI docs pages.

[nate-double-u]

Inviting @celestehorgan to discuss.

You had mentioned checking section.html’s template -- in this case it is identical to single.html (which may be its own problem). I agree that the issue is likely how the context is getting passed in, but I'm having trouble seeing where (my kingdom for a hugo debugger).

[nate-double-u]

Adding a {{ printf "%#v" . }} to the <header> of ~single.html~ section.html does generate some interesting results:

On http://localhost:1313/plugins/pkg/ns/:

But on http://localhost:1313/cni/code-of-conduct/ it generates no change:

Telling us that the incorrectly functioning breadcrumb/edit button are getting routed through the ~single.html~ section.html file. Now to hunt down where and why single.html gets called instead of section.html

[nate-double-u]

Sorry, updated the filenames for the test.

[nate-double-u]

See PR #43, restructuring the documentation into a much simpler, flatter structure has sorted this issue.