refactor: make detail user use bulma

src/fellchensammlung/templates/fellchensammlung/details/detail-user.html

@@ -1,4 +1,4 @@
-{% extends "fellchensammlung/base_generic.html" %}
+{% extends "fellchensammlung/base_bulma.html" %}
 {% load i18n %}
 
 {% block title %}<title>{{ user.get_full_name }}</title>{% endblock %}