add show_guided_tour value to User

This boolean value indicates whether the user wishes to be show the guided tour.
It defaults to True but will be able to be easily set to False.

bookwyrm/migrations/0151_user_show_guided_tour.py

@@ -0,0 +1,19 @@
+# Generated by Django 3.2.13 on 2022-06-13 01:59
+
+import bookwyrm.models.fields
+from django.db import migrations
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('bookwyrm', '0150_readthrough_stopped_date'),
+    ]
+
+    operations = [
+        migrations.AddField(
+            model_name='user',
+            name='show_guided_tour',
+            field=bookwyrm.models.fields.BooleanField(default=True),
+        ),
+    ]