[opening x-pack] ArcSight module documentation updates

[elasticmachine]

Original comment by @acchen97:

With the opening of x-pack and two different downloadable builds for LS, we'll need to update the ArcSight (x-pack basic) module documentation to better account for this change.

The current documentation only addresses the current "OSS-only LS build". We should assume they are using the "default LS build" which packages x-pack. As the instructions are split into the Smart Connector and Event Broker options, my proposal is that we yank these two areas of the current documentation and address it in a "Prerequisites" section that covers both input options:

• Steps 1-3 from each section
• First bullet in "Requirements" from each section

Prerequisites

1. These instructions assume you have Logstash, Elasticsearch, and Kibana already installed. The products you need are available to download and easy to install.
2. If using the Elastic Stack 6.2 and prior, please see the respective instructions for those versions.

Note: when they are available, we should like Logstash, Elasticsearch, and Kibana to their respective "default build" download links that include x-pack.

/cc @jakelandis @karenzone

[elasticmachine]

Original comment by @karenzone:

@acchen97: Is "default build" terminology that users will understand? (I'm not sure what that means, but that doesn't necessarily mean that users won't know.) Is there some other wording or explanation I can use to clarify?

[elasticmachine]

Original comment by @acchen97:

@karenzone changed some of the language to avoid the "default build" term. This build should be simply referred to as "Logstash", "Elasticsearch", or "Kibana". Also added a note for us to link directly to each of these build downloads for 6.3 when they are available.

[elasticmachine]

Original comment by @acchen97:

@karenzone have we had a chance to take a pass at this yet? Let me know if I can be of any assistance.

[elasticmachine]

Original comment by @karenzone:

@acchen97 Yes! Coming back around to it today. Stay tuned...

Update: Have a look at #9406

[karenzone]

Addressed: #9406

[acchen97]

Thanks @karenzone!