Teams must send their motivation letter

apps/participation/migrations/0003_team_motivation_letter.py

@@ -0,0 +1,19 @@
+# Generated by Django 3.0.11 on 2021-01-22 08:15
+
+from django.db import migrations, models
+import participation.models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('participation', '0002_auto_20210121_2206'),
+    ]
+
+    operations = [
+        migrations.AddField(
+            model_name='team',
+            name='motivation_letter',
+            field=models.FileField(blank=True, default='', upload_to=participation.models.get_motivation_letter_filename, verbose_name='motivation letter'),
+        ),
+    ]