terraform/website/layouts/guides.erb

<% wrap_layout :inner do %>
  <% content_for :sidebar do %>
    <ul class="nav docs-sidenav">
      <li<%= sidebar_current("guides-getting-started") %>>
        <a href="/intro/getting-started/install.html">Getting Started</a>
      </li>
      <li<%= sidebar_current("guides-writing-custom-terraform-providers") %>>
        <a href="/guides/writing-custom-terraform-providers.html">Writing Custom Providers</a>
      </li>
      <li<%= sidebar_current("guides-running-terraform-in-automation") %>>
        <a href="/guides/running-terraform-in-automation.html">Running Terraform in Automation</a>
      </li>
      <li<%= sidebar_current("guides-terraform-provider-development-program") %>>
        <a href="/guides/terraform-provider-development-program.html">Terraform Provider Development Program</a>
      </li>
    </ul>
  <% end %>

  <%= yield %>
<% end %>