@claude - Please create a docs PR for the Mattermost v11.8 feature work covering plugin metrics served through the standard /metrics endpoint.

Engineering PR to review:

• MM Build 2025 - Skadoosh - Serve plugin metrics to standard /metrics endpoint mattermost#34678

Goal:
Update the admin observability/metrics documentation so operators understand how plugin-provided metrics are exposed through the standard Mattermost /metrics endpoint.

Please follow these requirements:

• Review the linked PR directly before making changes.
• Extract the milestone version from the PR metadata and use it for any versioned release wording.
• Focus on admin/operator-visible observability behavior.
• Do not document implementation details, internal code structure, plugin internals, or technical architecture.
• Prefer updating existing metrics, monitoring, Prometheus, or observability docs.
• Keep the update concise and practical.

Please cover only behavior supported by PR evidence:

• Plugin metrics can be served through the standard Mattermost /metrics endpoint.
• Any required configuration or feature flag that admins must enable.
• How plugin metrics are identified or namespaced, if relevant to admins using Prometheus.
• Any operational caveats supported by PR evidence.

Use this capability framing:
Admins can collect plugin-provided Prometheus metrics from the standard Mattermost /metrics endpoint.

Target personas:

• System Admin
• IT Service Operations

Please avoid:

• Changelog edits
• Important upgrade notes
• Version archive pages
• Deprecated/removed feature pages
• Internal implementation details
• Speculating about plugin behavior not shown in the PR

After applying the docs update, provide:

1. Summary of changed files
2. Short explanation of the docs impact
3. Any open questions or items requiring SME review