feat: add comprehensive GitHub workflow and development tools

app/stiftung/serializers.py

@@ -0,0 +1,12 @@
+from rest_framework import serializers
+from .models import Person, Foerderung
+
+class PersonSerializer(serializers.ModelSerializer):
+    class Meta:
+        model = Person
+        fields = "__all__"
+
+class FoerderungSerializer(serializers.ModelSerializer):
+    class Meta:
+        model = Foerderung
+        fields = "__all__"