chore(root): remove DRF and django-filter dependencies

drop DRF and django-filter to make django_nepkit framework‑agnostic, simplify dependencies, and align with v0.2.2 breaking change.

example/example_project/settings.py

@@ -14,8 +14,6 @@ INSTALLED_APPS = [
     "django.contrib.messages",
     "django.contrib.staticfiles",
     "django_nepkit",
-    "rest_framework",
-    "django_filters",
     "demo",
 ]
 

example/example_project/urls.py

@@ -3,6 +3,6 @@ from django.urls import include, path
 
 urlpatterns = [
     path("admin/", admin.site.urls),
-    # path("nepkit/", include("django_nepkit.urls")),
+    path("nepkit/", include("django_nepkit.urls")),
     path("", include("demo.urls")),
 ]