Docs: Adds Vietnamese, Indonesian to DAC lang-selector.

        <select name="language" onchange="changeLangPref(this.value, true)">

          <option value="en" selected="selected">English</option>

          <option value="es">Español</option>

          <option value="in">Bahasa Indonesia</option>

          <option value="ja">日本語</option>

          <option value="ko">한국어</option>

          <option value="pt-br">Português Brasileiro</option>

          <option value="ru">Русский</option>

          <option value="vi">tiếng Việt</option>

          <option value="zh-cn">中文（简体)</option>

          <option value="zh-tw">中文（繁體)</option>

        </select>