chore(asta): add more spacing between button and checkbox

shiftregister/app/templates/asta.html

@@ -3,7 +3,7 @@
 {% block title %}AStA-Mitgliedschaft{% endblock %}
 
 {% block content %}
-<a class="button is-primary mb-2" href="https://member.asta-bbg.de/?next=https%3A%2F%2Fhelfen.kntkt.de%2Fasta">AStA-Formular</a>
+<a class="button is-primary mb-5" href="https://member.asta-bbg.de/?next=https%3A%2F%2Fhelfen.kntkt.de%2Fasta">AStA-Formular</a>
 <form action="" method="post">
     {% csrf_token %}
 {% for field in form %}