chore(server): add ai document link on admin panel (#13428)

close AF-2766
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#### PR Dependency Tree


* **PR #13428** 👈

This tree was auto-generated by
[Charcoal](https://github.com/danerwilliams/charcoal)

<!-- This is an auto-generated comment: release notes by coderabbit.ai
-->

## Summary by CodeRabbit

* **New Features**
* Configuration descriptions for the copilot plugin now include direct
links to relevant documentation for easier access to more information.

* **Style**
* Improved display of configuration descriptions to support and render
HTML content.

* **Refactor**
* The AI navigation item in the admin panel has been disabled and is no
longer visible.

<!-- end of auto-generated comment: release notes by coderabbit.ai -->

.docker/selfhost/schema.json

@@ -664,7 +664,7 @@
       "properties": {
         "enabled": {
           "type": "boolean",
-          "description": "Whether to enable the copilot plugin.\n@default false",
+          "description": "Whether to enable the copilot plugin. <br> Document: <a href=\"https://docs.affine.pro/self-host-affine/administer/ai\" target=\"_blank\">https://docs.affine.pro/self-host-affine/administer/ai</a>\n@default false",
           "default": false
         },
         "scenarios": {