Draft: Add docs

TODO:

<ul class="collapsible">
    <li>
      <div class="collapsible-header">{% trans "SchILD-NRW" %}</div>
      <div class="collapsible-body">
        <div class="alert info">
          <p>
            <i class="material-icons left">info</i>
            {% blocktrans %}
              SchILD-NRW provides export functions for basic data of students,
              teachers and guardians as CSV files. To generate CSV files in the correct format for the built-in import
              template, please use the following templates:
            {% endblocktrans %}
          </p>
        </div>
        <div class="collection">
          <a class="collection-item" href="{% static 'csv_import/schild_nrw/schild_aleksis_schueler.txt' %}">
            {% blocktrans %}SchILD-NRW CSV export template for students{% endblocktrans %}
          </a>
          <a class="collection-item" href="{% static 'csv_import/schild_nrw/schild_aleksis_lehrer.txt' %}">
            {% blocktrans %}SchILD-NRW CSV export template for teachers{% endblocktrans %}
          </a>
          <a class="collection-item" href="{% static 'csv_import/schild_nrw/schild_aleksis_eltern.txt' %}">
            {% blocktrans %}SchILD-NRW CSV export template for guardians{% endblocktrans %}
          </a>
        </div>
      </div>
    </li>
    <li>
      <div class="collapsible-header">{% trans "Pedasos" %}</div>
      <div class="collapsible-body">
        <div class="alert info">
          <p>
            <i class="material-icons left">info</i>
            {% blocktrans %}
              Pedasos has a tool called "List generator" which can be used to create own lists and export them in
              various variants. Please define the following lists in your Pedasos instance to use the predefined import
              templates and export them as CSV files:
            {% endblocktrans %}
          </p>
        </div>
        <table class="highlight">
          <thead>
          <tr>
            <th>{% trans "Column number" %}</th>
            <th>{% trans "Field value" %}</th>
          </tr>
          </thead>
        </table>
      </div>
    </li>
  </ul>

schild_aleksis_schueler.txt

schild_aleksis_lehrer.txt

schild_aleksis_eltern.txt