restructure to follow dep15

Use the project as the first and initial app instead of core, this follow django dep15
django/deps#98

Author: Tobi-De

{{ cookiecutter.project_name }}/{{ cookiecutter.project_name }}/core/apps.py renamed to {{ cookiecutter.project_name }}/{{ cookiecutter.project_name }}/apps.py

@@ -1,9 +1,9 @@
 from django.apps import AppConfig
 
 
-class CoreConfig(AppConfig):
+class {{ cookiecutter.project_name }}Config(AppConfig):
     default_auto_field = "django.db.models.BigAutoField"
-    name = "{{ cookiecutter.project_name }}.core"
+    name = "{{ cookiecutter.project_name }}"
 
     def ready(self):
         # This prevents django-fastdev from raising an error when accessing the signup page.

{{ cookiecutter.project_name }}/{{ cookiecutter.project_name }}/core/management/commands/__init__.py

@@ -132,7 +132,7 @@
 ]
 
 LOCAL_APPS = [
-    "{{ cookiecutter.project_name }}.core",
+    "{{ cookiecutter.project_name }}",
 ]
 
 if DEBUG: