docs: def register_app_activity():
      """
      Create watchers for models defined in settings.py.
      Once created, they will be passed over
      Activity.objects.follow_model(), which lives in managers.py
      """
      from django.conf import settings
      from django.contrib.contenttypes.models import ContentType
  
      from .models import Activity
  
      # TO-DO: Add check for existence of setting
      if not hasattr(settings, 'ACTIVITY_MONITOR_MODELS'):
          return
  
      for item in settings.ACTIVITY_MONITOR_MODELS:
          try:
              app_label, model = item['model'].split('.', 1)
              content_type = ContentType.objects.get(app_label=app_label, model=model)
              model = content_type.model_class()
              Activity.objects.follow_model(model)
  
          except ContentType.DoesNotExist:
              pass