fix(post_meta): default to localized date formatting (#1552)

Fixes #1611

See Hugo docs: https://gohugo.io/functions/time/format/#localization

Author: David-Guillot

layouts/partials/post_meta.html

@@ -1,7 +1,7 @@
 {{- $scratch := newScratch }}
 
 {{- if not .Date.IsZero -}}
-{{- $scratch.Add "meta" (slice (printf "<span title='%s'>%s</span>" (.Date) (.Date | time.Format (default "January 2, 2006" site.Params.DateFormat)))) }}
+{{- $scratch.Add "meta" (slice (printf "<span title='%s'>%s</span>" (.Date) (.Date | time.Format (default ":date_long" site.Params.DateFormat)))) }}
 {{- end }}
 
 {{- if (.Param "ShowReadingTime") -}}