Question: who pioneered animated movies with his short feature steamboat willie in 1928
[{'answer': 'Walt Disney', 'provenance': [{'wikipedia_id': '18943962', 'title': 'Steamboat Willie', 'start_paragraph_id': 1, 'start_character': 68, 'end_paragraph_id': 1, 'end_character': 79, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '18943962', 'title': 'Steamboat Willie', 'start_paragraph_id': 1, 'start_character': 0, 'end_paragraph_id': 1, 'end_character': 605, 'bleu_score': 0.9545695715275291, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 2493025874294934275}, 'section': 'Section::::Abstract.'}]}]