reorganize example/tutorial code and fix extension docs

Author: bckohan

check.sh

@@ -1,5 +1,5 @@
 poetry run ruff format
-poetry run ruff format --line-length 80 django_typer/examples
+poetry run ruff format --line-length 80 django_typer/tests/apps/examples
 poetry run ruff check --fix --select I
 poetry run ruff check --fix
 poetry run mypy django_typer

django_typer/tests/apps/backup/backup/management/commands/backup.py

@@ -0,0 +1,7 @@
+from django.apps import AppConfig
+
+
+class BasicExamplesConfig(AppConfig):
+    name = "django_typer.tests.apps.examples.basic"
+    label = name.replace(".", "_")
+    verbose_name = "Basic Examples"