feat(core): cmd+f search in doc function (#7040)

You can use the cmd+F shortcut key to trigger the FindInPage function.

packages/frontend/electron/src/preload/bootstrap.ts

@@ -1,6 +1,6 @@
 import { contextBridge } from 'electron';
 
-import { affine, appInfo, getElectronAPIs } from './electron-api';
+import { affine, appInfo, cmdFind, getElectronAPIs } from './electron-api';
 
 const { apis, events } = getElectronAPIs();
 
@@ -10,6 +10,7 @@ contextBridge.exposeInMainWorld('events', events);
 
 try {
   contextBridge.exposeInMainWorld('affine', affine);
+  contextBridge.exposeInMainWorld('cmdFind', cmdFind);
 } catch (error) {
   console.error('Failed to expose affine APIs to window object!', error);
 }