hazelnut.dev/templates/header.html

<header>
    <h1 class="site-title">{{ config.title }}</h1>
    <nav>
        {% for item in config.extra.menu %}
        <a href="{{ item.url | safe | replace(from="$BASE_URL", to=config.base_url) }}">
            {{ item.name }}
        </a>
        {% endfor %}
    </nav>
</header>