<header>
    <a href="/" id="banner" title="{{ site.title }}">{{ site.title }}</a>
</header>

<header role="banner">
    <a href="/" id="banner" title="{{ site.title }}">
        <h1>{{ site.title }}</h1>
    </a>
</header>

Implement <h1> and role in banner
Implement <h1> and role in banner
