blowfish/layouts/shortcodes/gist.html

<div class="gist-container">
  <script src="https://gist.github.com/{{- index .Params 0 -}}/{{- index .Params 1 -}}.js{{- if len .Params | eq 3 -}}
      ?file={{- index .Params 2 -}}
    {{- end -}}"></script>
</div>