Docs: Portable schema exporter example is missing Django bootstrap steps

[bctiemann]

Change Type

Correction

Proposed Changes

The Exporting a Schema section of docs/portable-schema.md shows a Python snippet calling export_cots() but does not explain that Django must be fully bootstrapped before any NetBox or plugin code can be imported.

Users running the snippet as a standalone script hit one of two errors:

1. ImproperlyConfigured: Requested setting FIELD_CHOICES, but settings are not configured. — DJANGO_SETTINGS_MODULE is not set.
2. AppRegistryNotReady: Apps aren't loaded yet. — DJANGO_SETTINGS_MODULE is set but django.setup() is never called.

Reported in discussion #534.

Proposed fix: expand the section to show two usage paths — manage.py nbshell (zero setup, recommended) and a standalone .py with django.setup() called before any imports — plus an admonition explaining the AppRegistryNotReady error.

[cleboo]

Let me add one more suggestion here: include a snippet for the full schema as well.

from netbox_custom_objects.schema.exporter import export_cots
from netbox_custom_objects.models import CustomObjectType
import json

cots = CustomObjectType.objects.all()
document = export_cots(cots)
print(json.dumps(document, indent=2))

That makes it easier for the non-django people like me 😉

[bctiemann]

Good call — added an all-COTs snippet alongside the filtered example in PR #541 (commit 88c7891). It now shows both:

# Export specific COTs by slug
cots = CustomObjectType.objects.filter(slug__in=["circuit", "device-profile"])

# Or export all at once
cots = CustomObjectType.objects.all()

Thanks for the suggestion!