www/blog.bryanroessler.com/_includes/gtm_body.html

{% if site.gtm %}
    <!-- Google Tag Manager (noscript) -->
    <noscript><iframe src="https://www.googletagmanager.com/ns.html?id={{ site.gtm }}"
    height="0" width="0" style="display:none;visibility:hidden"></iframe></noscript>
    <!-- End Google Tag Manager (noscript) -->
{% endif %}