hugo-book-theme/layouts/partials/docs/post-meta.html

{{ $dateFormat := default "January 2, 2006" .Site.Params.BookDateFormat }}
{{ if or .Date .Params.tags }}
<div>
{{ with .Date}}
  <h5>{{ .Format $dateFormat }}</h5>
{{ end }}

{{ range $term, $_ := .Site.Taxonomies }}
  {{ with $list := index $.Params $term }}
    {{ range $n, $single := $list }}{{ if $n }}, {{ end }}
      {{ with $.Site.GetPage (printf "/%s/%s" $term $single) }}
        <a href="{{ .RelPermalink }}">{{ $single }}</a>
      {{- end }}
    {{- end }}
    <br />
  {{ end }}
{{ end }}

</div>
{{ end }}