add info about content intellisense (#12164)

packages/astro/src/@types/astro.ts

@@ -2173,7 +2173,7 @@ export interface AstroUserConfig {
 		 * }
 		 * ```
 		 *
-		 * To use this feature with the Astro VS Code extension, you must also enable the `astro.content-intellisense` option in your VS Code settings. For editors using the Astro language server directly, pass the `contentIntellisense: true` initialization parameter to enable this feature.
+		 * To use this feature with the Astro VS Code extension, you must also enable the `astro.content-intellisense` option in your VS Code settings. For editors using the Astro language server directly, pass the `contentIntellisense: true` initialization parameter to enable this feature. See the [content Intellisense implementation PR](https://github.com/withastro/language-tools/pull/915) for more details about this early feature.
 		 */
 		contentIntellisense?: boolean;