am 16add46c: Docs: Adding localized TOC for Preview docs.

<ul id="nav">

  <li class="nav-section">

    <div class="nav-section-header empty"><a href="<?cs var:toroot ?>preview/overview.html">

      Program Overview</a></div>

    <div class="nav-section-header empty"><a href="<?cs var:toroot ?>preview/overview.html"

   es-lang="Información general del programa"

   ja-lang="プログラム概要"

   ko-lang="프로그램 개요"

   pt-br-lang="Visão geral do programa"

   ru-lang="Обзор программы"

   zh-cn-lang="计划概览"

   zh-tw-lang="程式總覽">Program Overview

      </a></div>

  </li>

  <li class="nav-section">

    <div class="nav-section-header empty"><a href="<?cs var:toroot ?>preview/download.html">

      Downloads</a></div>

  </li>

  <li class="nav-section">

    <div class="nav-section-header"><a href="<?cs var:toroot ?>preview/api-overview.html">

      API Overview</a></div>

    <div class="nav-section-header"><a href="<?cs var:toroot ?>preview/api-overview.html"

      es-lang="Información general de la API"

      ja-lang="API の概要"

      ko-lang="API 개요"

      pt-br-lang="Visão geral da API"

      ru-lang="Обзор API-интерфейсов"

      zh-cn-lang="API 概览"

      zh-tw-lang="API 總覽">API Overview

      </a></div>

      <ul>

        <li><a href="<?cs var:toroot ?>preview/features/runtime-permissions.html">

          Permissions</a></li>

        <li><a href="<?cs var:toroot ?>preview/features/runtime-permissions.html"

      es-lang="Permisos"

      ja-lang="パーミッション"

      ko-lang="권한"

      pt-br-lang="Permissões"

      ru-lang="Разрешения"

      zh-cn-lang="权限"

      zh-tw-lang="權限">Permissions

          </a></li>

        <li><a href="<?cs var:toroot ?>preview/features/app-linking.html">

          App Links</a></li>

        <li><a href="<?cs var:toroot ?>preview/backup/index.html">

  </li>

  <li class="nav-section">

    <div class="nav-section-header empty"><a href="<?cs var:toroot ?>preview/behavior-changes.html">

      Behavior Changes</a></div>

    <div class="nav-section-header empty"><a href="<?cs var:toroot ?>preview/behavior-changes.html"

      es-lang="Cambios en los comportamientos"

      ja-lang="動作の変更点"

      ko-lang="동작 변경"

      pt-br-lang="Mudanças de comportamento"

      ru-lang="Изменения в работе"

      zh-cn-lang="行为变更"

      zh-tw-lang="行為變更">Behavior Changes

       </a></div>

  </li>

  <li class="nav-section">

    <div class="nav-section-header empty"><a href="<?cs var:toroot ?>preview/samples.html">