wagtail_bakerydemo/bakerydemo/jinja2/base/include/header-index.html

<div class="container">
    <div class="row">
        <div class="col-md-12">
            <h1 class="index-header__title">{{ page.title }}</h1>
        </div>
        <div class="col-sm-12 col-md-7">
            {% if page.introduction %}
                <p class="index-header__introduction">{{ page.introduction }}</p>
            {% endif %}
        </div>
    </div>
</div>