[Documentation]: Accurate and Detailed Documentation

[afeefghannam89]

Describe the improvements you'd like.

We should be more transparent with our documentation. Users of this collection should not have to dive deep into the Ansible code just to understand how to use the variables or how to set up the Elastic Stack (or any of its components) individually. Clear and reasonably detailed documentation also saves a lot of time during debugging. It doesn't harm when the same information in this collection are also documented by the vendor.

Here is an example of a problem:

ansible-collection-elasticstack/docs/role-repos.md

Line 23 in e21bb61

Please note that no `oss` versions are available for Elastic Stack later than `7`. This role will fail if you try to install them.

From that sentence, I understood that all Elastic Stack components are not available in an OSS variant for releases 8 and 9. That is not entirely correct. There are no OSS packages for Kibana and Elasticsearch, but OSS packages do exist for Logstash and Filebeat. The Logstash package is named logstash-oss, while the Filebeat package does not include the -oss suffix. I verified the package availability on RHEL 8.

The failing tasks for Kibana and Elasticsearch related to OSS being available only for version 7 are correct. It is also correct that such tasks do not exist for Logstash and Filebeat. However, to fully understand the reasoning behind this, one has to check the Elasticsearch documentation and perform local testing.

What I want to say is that a bit more explanation in this case would have saved a significant amount of debugging time.

What do you think @widhalmt @Wintermute2k6 ?