Add contest freeze

judge/migrations/0139_contest_freeze_after.py

@@ -0,0 +1,23 @@
+# Generated by Django 3.2.16 on 2022-11-18 06:11
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ("judge", "0138_bookmark_makebookmark"),
+    ]
+
+    operations = [
+        migrations.AddField(
+            model_name="contest",
+            name="freeze_after",
+            field=models.DurationField(
+                blank=True,
+                help_text="Format hh:mm:ss. For example, if you want to freeze contest after 2 hours, enter 02:00:00",
+                null=True,
+                verbose_name="freeze after",
+            ),
+        ),
+    ]