added style mimicking piepelines

data/raw/styling/test_missing_fields.jsonl

@@ -0,0 +1,5 @@
+{"text": "Hello world", "styled_text": "Greetings, world."}
+{"styled_text": "This is a formal greeting."}
+{"text": "How are you?", "styled_text": "How are you doing?"}
+{"text": null, "styled_text": "Empty input example."}
+{"styled_text": "Another example with no input."}