docs(self-hosted): Restructure experimental section into 'Production Enhancements' and 'Optional Features'

[aldy505]

DESCRIBE YOUR PR

These pages were never experimental, most of them are battle tested and enhances the operational side of self-hosted. Marking it as experimental confuses newcomers.

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SLA

• Teamwork makes the dream work, so please add a reviewer to your PRs.
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• Checked Vercel preview for correctness, including links
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Project	Deployment	Preview	Comments	Updated (UTC)
develop-docs	Ready	Preview	Comment	Nov 2, 2025 7:43am

1 Skipped Deployment

Project	Deployment	Preview	Comments	Updated (UTC)
sentry-docs	Ignored	Preview		Nov 2, 2025 7:43am

[aldy505]

Turns out I need to add index.md for each subfolders