deliver documentation does not explain Deliverfile

[simonbromberg]

The docs for deliver mention the Deliverfile in passing, but the page does not ever introduce the concept anywhere or have any examples / instructions on how to set one up.

Went through the documentation my first time using fastlane and didn't even know there was an option to use a Deliverfile, and only realized it was a thing because of other Github issues posted on the fastlane repo.

[KrauseFx]

Nice catch, thanks for reporting this, we'll be working on a fix 👍

[janpio]

File to change lives here: https://github.com/fastlane/fastlane/blob/master/fastlane/lib/fastlane/actions/docs/upload_to_app_store.md.erb