Create cursor pagination examples

[jkimbo]

Building a generic cursor based pagination api into strawberry is going to be tricky. So for the time being we should add some examples on how to implement it in your project.

An example of how to do it with Django and an example of how to do it with Sqlalchemy.

(For the Django implementation we could use https://github.com/photocrowd/django-cursor-pagination)