docs(api.js): fix heading level in window api docs
* ```
* It is recommended to allowlist only the APIs you use for optimal bundle size and security.
*
- * # Window events
+ * ## Window events
*
- * Events can be listened using `appWindow.listen`:
+ * Events can be listened to using `appWindow.listen`:
* ```typescript
* import { appWindow } from "@tauri-apps/api/window";
* appWindow.listen("my-window-event", ({ event, payload }) => { });
