text: Title: Add new step to `piccolo asgi new` for media storage
  Body: When running the `piccolo asgi new` command to create a new app, it asks you some questions:
  
  <img width="535" alt="Screenshot 2022-08-27 at 15 22 14" src="https://user-images.githubusercontent.com/350976/187034384-776b9be0-c4a4-490a-b464-c2bd73ae3be0.png">
  
  It would be good if there was one more question - 'Use S3 for media storage?'. It's a fairly simple modification to [this file](https://github.com/piccolo-orm/piccolo/blob/master/piccolo/apps/asgi/commands/new.py).
  
  If they answer 'y' to 'Use S3?' we will change the following line to `piccolo_admin[s3]`:
  
  https://github.com/piccolo-orm/piccolo/blob/305819612bb935cef25804667b223478f6ad71b7/piccolo/apps/asgi/commands/templates/app/requirements.txt.jinja#L5
  
  In the future we may add a ``media.py`` to the template showing how S3 is configured, but that can come in the future.
  
  
  
  
  