update field names

src/pdf_filler.py

@@ -28,15 +28,15 @@ def build_field_dict(
       - ``person.name``
       - ``monat_jahr``
       - ``antragsnummer``
-      - ``ort``
+      - ``unterschrift.ort``  (field name configurable via ``pdf_field_ort``)
-      - ``erstellungsdatum``
+      - ``unterschrift.datum`` (field name configurable via ``pdf_field_erstellungsdatum``)
 
     Per-row fields (index 0–22, max 23 rows):
       - ``datum.N``
       - ``anwesend.N``
       - ``ist.N``
       - ``plan.N``
-      - ``pauschale.N``
+      - ``pauschale_5.N``  (prefix configurable via ``pdf_pauschale_prefix``)
     """
     if config is None:
         config = load_config()