code: func breadcrumbs(path string, ver string) []breadcrumb {
  	out := []breadcrumb{
  		{Title: "[root]", Href: prefixPageURL("")},
  	}
  	if path != "" {
  		chunks := strings.Split(path, "/")
  		for i, ch := range chunks {
  			out = append(out, breadcrumb{
  				Title: ch,
  				Href:  prefixPageURL(strings.Join(chunks[:i+1], "/")),
  			})
  		}
  	}
  
  	// This is a breadcrumb path to an instance of package named 'path'. Fix URL
  	// of the crumb that corresponds to the package to point to the package page,
  	// not the prefix page.
  	if ver != "" {
  		out[len(out)-1].Href = packagePageURL(path, "")
  		out = append(out, breadcrumb{
  			Title: ver,
  			Href:  instancePageURL(path, ver),
  		})
  	}
  
  	out[len(out)-1].Last = true
  	return out
  }
docs: // breadcrumbs builds a data for the breadcrumps navigation element.
  //
  // It contains a prefix path, where each element is clickable.