terraform/website/source/layouts/fastly.erb

<% wrap_layout :inner do %>
    <% content_for :sidebar do %>
        <div class="docs-sidebar hidden-print affix-top" role="complementary">
            <ul class="nav docs-sidenav">
                <li<%= sidebar_current("docs-home") %>>
                    <a href="/docs/providers/index.html">All Providers</a>
                </li>

                <li<%= sidebar_current("docs-fastly-index") %>>
                    <a href="/docs/providers/fastly/index.html">Fastly Provider</a>
                </li>

                <li<%= sidebar_current("docs-fastly-datasource") %>>
                <a href="#">Data Sources</a>
                    <ul class="nav nav-visible">
                        <li<%= sidebar_current("docs-fastly-datasource-ip_ranges") %>>
                            <a href="/docs/providers/fastly/d/ip_ranges.html">fastly_ip_ranges</a>
                        </li>
                    </ul>
                </li>

                <li<%= sidebar_current("docs-fastly-resource") %>>
                    <a href="#">Resources</a>

                    <ul class="nav nav-visible">
                        <li<%= sidebar_current("docs-fastly-resource-service-v1") %>>
                            <a href="/docs/providers/fastly/r/service_v1.html">service_v1</a>
                        </li>
                    </ul>

                </li>
            </ul>
        </div>
    <% end %>

    <%= yield %>
<% end %>