docs(obsidian): add service documentation page

[AI-Joe-code]

Summary

Adds a documentation page for Obsidian - a popular knowledge base and note-taking app. This Coolify template runs Obsidian as a Linux desktop container using the LinuxServer.io image, streaming the GUI to the browser via Selkies WebSocket over HTTPS.

Changes

• content/docs/services/obsidian.mdx - new service documentation page
• public/images/services/obsidian-logo.svg - service logo
• src/generated/services.json - regenerated (added Obsidian entry under Productivity)
• content/docs/services/all.mdx - regenerated (added Obsidian listing)

Related

• Service Template Request: Add Service: Obsidian coolify#6526
• Template PR: feat(service): add Obsidian one-click template coolify#10704
• Upstream: https://docs.linuxserver.io/images/docker-obsidian

Checklist

• Frontmatter has title, description, and category
• category matches an existing category in catalog.md exactly
• Logo file present at public/images/services/obsidian-logo.svg
• External links have ?utm_source=coolify.io
• No em-dashes anywhere in the .mdx file
• Logo uses <ZoomImage> component (not plain markdown ![]())
• Callouts use <Callout type=warn> / <Callout type=info> (not ::: warning)
• bun run generate:services run - entry visible in services.json and all.mdx