Closes#21130
Adds documentation for Google Antigravity IDE integration, following the
same pattern as Cursor and Windsurf (dedicated page for desktop IDEs).
**Changes:**
- `docs/user-guides/workspace-access/antigravity.md` — New dedicated
page with install guide, Coder extension setup, and template
configuration example using the [Antigravity registry
module](https://registry.coder.com/modules/coder/antigravity)
- `docs/user-guides/workspace-access/index.md` — Added Antigravity IDE
section alongside Cursor and Windsurf
- `docs/manifest.json` — Added sidebar navigation entry after Windsurf
Antigravity uses the `antigravity://` protocol (added in #20873) and the
built-in `/icon/antigravity.svg` icon (added in #21068). The [registry
module](https://registry.coder.com/modules/coder/antigravity) wraps
`vscode-desktop-core` with `protocol = "antigravity"`.
Created on behalf of @matifali
Co-authored-by: blink-so[bot] <211532188+blink-so[bot]@users.noreply.github.com>
blinkagent[bot]