converse.js/docs/source/_templates/layout.html

{# Import the theme's layout. #}
{% extends "!layout.html" %}

{# Custom CSS overrides #}
{% set css_files = css_files + ['_static/style.css', "../../css/converse.min.css"] %}
{% set script_files = script_files + ["../../dist/converse.min.js", "../../analytics.js"] %}

{# Add some extra stuff before and use existing with 'super()' call. #}
{% block footer %}
    {{ super() }}
    <script>
        converse.initialize({
            bosh_service_url: 'https://conversejs.org/http-bind/',
        });
    </script>
{% endblock %}