Add migration file for new database model

InvenTree/part/migrations/0072_bomitemsubstitute.py

@@ -0,0 +1,22 @@
+# Generated by Django 3.2.5 on 2021-10-12 23:24
+
+from django.db import migrations, models
+import django.db.models.deletion
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('part', '0071_alter_partparametertemplate_name'),
+    ]
+
+    operations = [
+        migrations.CreateModel(
+            name='BomItemSubstitute',
+            fields=[
+                ('id', models.AutoField(auto_created=True, primary_key=True, serialize=False, verbose_name='ID')),
+                ('bom_item', models.ForeignKey(help_text='Parent BOM item', on_delete=django.db.models.deletion.CASCADE, related_name='substitutes', to='part.bomitem', verbose_name='BOM Item')),
+                ('part', models.ForeignKey(help_text='Substitute part', limit_choices_to={'component': True}, on_delete=django.db.models.deletion.CASCADE, related_name='substitute_items', to='part.part', verbose_name='Part')),
+            ],
+        ),
+    ]