chore: bring Marcos out of retirement

[marcoscaceres]

Would like to resume editorial duties as this spec is not now a joint deliverable with WebApps WG.

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Preview | Diff

[rakuco]

lgtm!

[rakuco]

Deployment failed with

  Specberus Errors:
    The user with id 39125 is not participating in the group producing this document.
      {
        name: 'headers.editor-participation',
        section: 'front-matter',
        rule: 'editorSection'
      }

cc @himorin

[himorin]

ah, it's a mix of multiple issues,,,

• this specification needs to be republished as joint deliverable, including marking as joint deliverable in database
• pubrules added a new rule to ensure all editors to be participants of producing WG