ci(release_workspace): add additional checks and document workflow

[BethGriggs]

• Refactored the workflow to infer the branch from the workspace name using the pattern workspace/${workspace}
• Removed the unused branch input from the workflow
• Added handling for missing GitHub events in release checks
• Introduced logic to set npm publish tag (latest or maintenance)
• Added initial plugin maintainer guide for patching older release lines

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:heavy_check_mark: Checklist

• [ ] A changeset describing the change and affected packages. (more info)
• [x] Added or updated documentation
• [ ] Tests for new functionality and regression tests for bug fixes
• [ ] Screenshots attached (for UI changes)
• [x] All your commits have a Signed-off-by line in the message. (more info)