[RFC] Create ELF Fieldset - Stage 3 Proposal

[peasead]

• Have you signed the contributor license agreement?
• Have you followed the contributor guidelines?
• For proposing substantial changes or additions to the schema, have you reviewed the RFC process?
• If submitting code/script changes, have you verified all tests pass locally using make test?
• If submitting schema/fields updates, have you generated new artifacts by running make and committed those changes?
• Is your pull request against main? Unless there is a good reason otherwise, we prefer pull requests against main and will backport as needed.
• Have you added an entry to the CHANGELOG.next.md?

[devonakerr]

@peasead, concise update: LGTM

[ebeahan]

@elasticmachine run elasticsearch-ci/docs

[kgeller]

@elasticmachine run elasticsearch-ci/docs

[ebeahan]

Stage 3 checklist:

• Opened pull request for this candidate revising the existing candidate
• Included multiple real world example source documents
• Existing or newly raised questions and concerns are addressed
• No objections from sponsor, ECS team, or subject matter experts

[github-actions]

This PR is stale because it has been open for 60 days with no activity.