Add the basics of the CMS

[danniel]

Create the basics of the CMS page system. You can create and edit pages from Django Admin (no WYSIWYG editor for now).

Published pages can be accessed on the frontend by using the slug ("url_name") generated from the title, like: http://localhost:8000/page/titlul-paginii/

Non-published pages will raise an Error 404.

[costibleotu]

You should autogenerate the slug on save (see - https://docs.djangoproject.com/en/2.2/ref/utils/#django.utils.text.slugify)

[costibleotu]

You should rename url_name to slug