Append petition notification

scipost/templates/scipost/personal_page.html

@@ -119,6 +119,10 @@
                     {# END: Scientist fields #}
                     {% endif %}
 
+                    <h3 class="text-danger">Scientists, please help us out!</h3>
+                    <p>If it is not listed on our Partners page, please encourage your institution (through a librarian, director, ...) to join by <a class="h3 text-blue" href="{% url 'petitions:petition' slug='join-SPB' %}">signing our petition</a>.</p>
+                    <hr>
+
                   {% if 'SciPost Administrators' in user_groups %}
                       <h3>You are a SciPost Administrator.</h3>
                   {% endif %}