[Feature] Improve GitHub Action documentation and workflow

[peternied]

Is your feature request related to a problem? Please describe

OpenSearch has many checks that are run on pull requests which are displayed 'below the fold' of the UX in the pull request page, this makes them easy to overlook, especially when some checks report status directly into the pull request comments.

Improving documentation and instruction on how to troubleshoot a failures would lower the burden on maintainers and help contributors unblock themselves.

Describe the solution you'd like

Lets consolidate the 'result' comments that are featured in the pull request to include checks that are required before a pull request is merged along with links to documentation that describe what these checks are and how to troubleshoot.

Related component

Other

Describe alternatives you've considered

This could also be a new markdown document under .github/workflow that includes details about what each workflow is and how that are used that would be referenced in the project.

Additional context

No response

[peternied]

[Triage - attendees 1 2 3 4 5 6 7 8]
@peternied Thanks for creating this issue.