Add plan follower model and configuration

froide_govplan/apps.py

@@ -5,3 +5,10 @@ from django.utils.translation import gettext_lazy as _
 class FroideGovPlanConfig(AppConfig):
     name = "froide_govplan"
     verbose_name = _("GovPlan App")
+
+    def ready(self):
+        from froide.follow.configuration import follow_registry
+
+        from .configuration import GovernmentPlanFollowConfiguration
+
+        follow_registry.register(GovernmentPlanFollowConfiguration())