Adds description field to shelf

bookwyrm/migrations/0100_shelf_description.py

@@ -0,0 +1,18 @@
+# Generated by Django 3.2.5 on 2021-09-28 23:20
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ("bookwyrm", "0099_readthrough_is_active"),
+    ]
+
+    operations = [
+        migrations.AddField(
+            model_name="shelf",
+            name="description",
+            field=models.TextField(blank=True, max_length=500, null=True),
+        ),
+    ]