Docs: Feedback for Logging Configuration

Page: https://github.com/hazelcast/imdg-docs/blob/v4.2/docs/modules/clusters/pages/logging-configuration.adoc

According to the feedback we got from a user, following this chapter was not sufficient to really change the logging configuration. The user was a DevOps person which had little knowledge about Java.
In particular, he mentioned that the docs ask for putting some JARs on the classpath, but there's no link where to download the JARs and where is the classpath.
The other issue reported has already been fixed: https://github.com/hazelcast/imdg-docs/pull/61/files

I think we need to go through this chapter really end to end, maybe together with the Support team, to make sure that it's easy to digest and make it quite like a "getting started" guide.