ref: cb84d9816956c4de9353bc6d62d33723581bd3b4
dir: /tpl/tplimpl/embedded/templates/shortcodes/param.html/
{{- $name := (.Get 0) -}}
{{- with $name -}}
{{- with ($.Page.Param .) }}{{ . }}{{ else }}{{ errorf "Param %q not found: %s" $name $.Position }}{{ end -}}
{{- else }}{{ errorf "Missing param key: %s" $.Position }}{{ end -}}