Improve documentation for S3 uploads

[mnapoli]

This follows https://github.com/getlift/lift/releases/tag/1.35.0

Example config before:

    storage:
        type: storage
        lifecycleRules:
            -   prefix: tmp/
                expirationInDays: 1
        extensions:
            bucket:
                Properties:
                    OwnershipControls:
                        Rules:
                            -   ObjectOwnership: BucketOwnerPreferred
                    CorsConfiguration:
                        CorsRules:
                            -   AllowedOrigins:
                                    - ${construct:website.url}
                                AllowedHeaders:
                                    - '*'
                                AllowedMethods:
                                    - PUT

After:

    storage:
        type: storage
        lifecycleRules:
            -   prefix: tmp/
                expirationInDays: 1
        allowAcl: true
        cors: ${construct:website.url}