feat(api): Add public API feature flag index endpoint

ref: #673 #663

app/devops/urls_public.py

@@ -0,0 +1,18 @@
+from rest_framework.routers import DefaultRouter, SimpleRouter
+
+from devops.viewsets import (
+    feature_flag_endpoints,
+    public_feature_flag,
+)
+
+
+
+app_name = "devops"
+
+router = SimpleRouter(trailing_slash=False)
+
+router.register('flags', feature_flag_endpoints.Index, basename='_api_v2_flags')
+
+router.register('(?P<organization_id>[0-9]+)/flags/(?P<software_id>[0-9]+)', public_feature_flag.ViewSet, basename='_public_api_v2_feature_flag')
+
+urlpatterns = router.urls