Add Service: Obsidian

[simplerethink]

Obsidian is a note-taking app that lets you create, link, and organize your notes on your device, with hundreds of plugins and themes to customize your workflow. You can also publish your notes online, access them offline, and sync them securely with end-to-end encryption.

Website: https://obsidian.md/
Docker Docs: https://github.com/linuxserver/docker-obsidian

[AI-Joe-code]

Both PRs are now open:

• Docs PR: docs(obsidian): add service documentation page coolify-docs#651 — service documentation page
• Template PR: feat(service): add Obsidian one-click template #10704 — one-click deploy template

This discussion can be closed once both PRs are merged.