[8471] apps/contrib/templates: add template file for alerts

[jonasDarley3000]

Describe your changes I updated the alerts with regards to the new design

Tasks

• [x] PR name contains story or task reference
• [ ] Steps to recreate and test the changes
• [ ] Documentation (docs and inline)
• [ ] Tests (including n+1 and django_assert_num_queries where applicable)
• [x] Changelog