{{ range $section, $content := .Site.Data.data }}
{{ $title := substr $section 3 }}
<span class="title">{{ $title }}</span>
<ul>
    {{ range $link_name, $link_href := $content -}}
    {{ $link_name := substr $link_name 3 -}}
    <li><a href="{{ $link_href }}">{{ $link_name }}</a></li>
    {{ end }}
</ul>
{{ end }}