Merge branch 'feature-json-export' into 'main'

.gitlab-ci.yml

AKModel/availability/models.py

AKModel/forms.py

AKModel/locale/de_DE/LC_MESSAGES/django.po

AKModel/models.py

AKModel/templates/admin/AKModel/ak_json_export.html

AKModel/urls.py

AKModel/views/ak.py

AKModel/views/manage.py

AKModel/views/status.py

AKPlan/locale/de_DE/LC_MESSAGES/django.po

AKPlanning/locale/de_DE/LC_MESSAGES/django.po

AKScheduling/models.py

AKSubmission/locale/de_DE/LC_MESSAGES/django.po

INSTALL.md

Utils/setup.sh