Webhooks: Add comment field (#3095)

src/pretix/api/migrations/0010_webhook_comment.py

@@ -0,0 +1,18 @@
+# Generated by Django 3.2.17 on 2023-02-07 12:18
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('pretixapi', '0009_auto_20221217_1847'),
+    ]
+
+    operations = [
+        migrations.AddField(
+            model_name='webhook',
+            name='comment',
+            field=models.CharField(max_length=255, null=True),
+        ),
+    ]