Chore/566 add apigateway property to provider in documentation example

[tvhees]

This PR does not include functional changes but corrects documentation which would otherwise lead to a deployment error if followed.

[lopburny]

@tvhees LGTM!

[horike37]

:tada: This PR is included in version 3.14.0 :tada:

The release is available on:

• npm package (@latest dist-tag)
• GitHub release

Your semantic-release bot :package::rocket: