Port changes made to Beats Asciidoc files during docs freeze into 9.0 Markdown docs.

[kilfoyle]

Port changes made to Beats Asciidoc files during docs freeze into 9.0 Markdown docs.

Docs were frozen from Jan.30 - Feb.20. However, Beats Markdown docs have yet to be merged (see elastic/beats#42897 ).

Full instructions from 2025-03-05 Docs Team meeting:

• In the source code repos, check commits that were opened in main/master and backported to 9.0, or committed directly to 9.0 during the Docs freeze (or other version branches for repos that do not use the 9.0 Stack version).
• Reconcile any differences between the AsciiDoc changes and migrated Markdown files.
• Copy the migrated Markdown files from main/master to 9.0 (or other version branches for repos that do not use the 9.0 Stack version). Backporting for all PRs that contain Docs files will now be required, however, the plan is still to publicly display only the main/master Docs files.
• In https://github.com/elastic/docs-eng-team/issues/130, review your assigned repo and determine how and if files should be copied to another branch.

As of 2025-03-05, the following PRs have docs content for 9.0 that will need to be merged into the Markdown docs when they're ready:

• [9.0](backport #41845) feat: drop init.d support and go-daemon binaries beats#42720
• [Journald] update include_matches beats#42517
• [9.x] Fully remove Enterprise Search from Metricbeat beats#42915