put intro text in a django block

newsletter/templates/newsletter/subscriber_form_content.html

 {% load i18n %}
 
 {% csrf_token %}
+
+{% block newsletter-text %}
 <p>{% trans 'Every Monday, the news of the Panik week:' %}</p>
+{% endblock %}
 
 <input required name="email" type="email" placeholder="{% trans "your email address" %}">
 <div style="display: none;">