warning for develop examples

Signed-off-by: Michele Dolfi <dol@zurich.ibm.com>

docs/examples/develop_formula_understanding.py

@@ -1,3 +1,7 @@
+# WARNING
+# This example demonstrates only how to develop a new enrichment model.
+# It does not run thr actual formula understanding model.
+
 import logging
 from pathlib import Path
 from typing import Iterable

docs/examples/develop_picture_enrichment.py

@@ -1,3 +1,7 @@
+# WARNING
+# This example demonstrates only how to develop a new enrichment model.
+# It does not run thr actual picture classifier model.
+
 import logging
 from pathlib import Path
 from typing import Any, Iterable