Make sending references configurable

core/migrations/0024_ad_send_reference.py

@@ -0,0 +1,18 @@
+# Generated by Django 4.1.7 on 2023-03-14 09:36
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('core', '0023_alter_trade_linked'),
+    ]
+
+    operations = [
+        migrations.AddField(
+            model_name='ad',
+            name='send_reference',
+            field=models.BooleanField(default=True),
+        ),
+    ]