add text orientation on transcriptions, editable in admin

arkindex/documents/migrations/0044_transcription_orientation.py

-# Generated by Django 3.2.6 on 2021-10-22 08:27
-
-import enumfields.fields
-from django.db import migrations
-
-import arkindex.documents.models
-
-
-class Migration(migrations.Migration):
-
-    dependencies = [
-        ('documents', '0043_element_creator'),
-    ]
-
-    operations = [
-        migrations.AddField(
-            model_name='transcription',
-            name='orientation',
-            field=enumfields.fields.EnumField(default='horizontal-lr', enum=arkindex.documents.models.TextOrientation, max_length=50),
-        ),
-    ]