Use edit date to track is status has been updated

bookwyrm/migrations/0109_status_edited_date.py

@@ -0,0 +1,19 @@
+# Generated by Django 3.2.5 on 2021-10-15 15:54
+
+import bookwyrm.models.fields
+from django.db import migrations
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ("bookwyrm", "0108_alter_user_preferred_language"),
+    ]
+
+    operations = [
+        migrations.AddField(
+            model_name="status",
+            name="edited_date",
+            field=bookwyrm.models.fields.DateTimeField(blank=True, null=True),
+        ),
+    ]