_includes/comments-providers/scripts.html

{% if site.comments.provider and page.comments %}

{% case site.comments.provider %}
{% when "disqus" %}
  {% include /comments-providers/disqus.html %}
{% when "discourse" %}
  {% include /comments-providers/discourse.html %}
{% when "facebook" %}
  {% include /comments-providers/facebook.html %}
{% when "google-plus" %}
  {% include /comments-providers/google-plus.html %}
{% when "staticman" %}
  {% include /comments-providers/staticman.html %}
{% when "custom" %}
  {% include /comments-providers/custom.html %}
{% endcase %}

{% endif %}