Update for new Hugo versions

Signed-off-by: Danila Fedorin <danila.fedorin@gmail.com>

layouts/_partials/uniquebyseries.html

@@ -0,0 +1,14 @@
+{{- $scratch := .scratch -}}
+{{- $scratch.Set "pages" slice -}}
+{{- $tmpScratch := newScratch -}}
+{{- range $post := (where (where site.Pages.ByDate.Reverse "Section" "blog") ".Kind" "!=" "section") -}}
+{{- $term := index ($post.GetTerms "series") 0 -}}
+{{- if (and $term (not ($term.Param "donotunique"))) -}}
+{{- if not ($tmpScratch.Get $term.Permalink) -}}
+{{- $tmpScratch.Set $term.Permalink true -}}
+{{- $scratch.Add "pages" $post -}}
+{{- end -}}
+{{- else -}}
+{{- $scratch.Add "pages" $post -}}
+{{- end -}}
+{{- end -}}