[DOCS] Update scrolling document.asciidoc

[salihklc]

adding more detail to example code

[elasticmachine]

Since this is a community submitted pull request, a Jenkins build has not been kicked off automatically. Can an Elastic organization member please verify the contents of this patch and then kick off a build manually?

[cla-checker-service[bot]]

❌ Author of the following commits did not sign a Contributor Agreement: f41976b14b58f8e863a325e9a4188708a0cf1b84

Please, read and sign the above mentioned agreement if you want to contribute to this project

[stevejgordon]

Thanks for your contribution, @salihklc. I will close this PR as we're reworking the 8.0 documentation significantly.