Add position field for passages

Signed-off-by: Emmy D'Anello <emmy.danello@animath.fr>

registration/migrations/0008_alter_payment_valid.py

@@ -0,0 +1,19 @@
+# Generated by Django 4.2 on 2023-04-06 22:05
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+    dependencies = [
+        ("registration", "0007_alter_participantregistration_options_and_more"),
+    ]
+
+    operations = [
+        migrations.AlterField(
+            model_name="payment",
+            name="valid",
+            field=models.BooleanField(
+                default=False, null=True, verbose_name="payment valid"
+            ),
+        ),
+    ]