Transcription-Entities link in database/Simple API endpoint

arkindex/documents/api/elements.py

arkindex/documents/api/entities.py

...x/documents/migrations/0006_transcribed_entities_table.py

arkindex/documents/models.py

arkindex/documents/serializers/elements.py

arkindex/documents/serializers/entities.py

arkindex/documents/serializers/ml.py

arkindex/documents/tests/test_elements_api.py

arkindex/project/api_v1.py

openapi/patch.yml