Update preload.js

Expose a new IPC channel

preload.js

@@ -1,8 +1,9 @@
-const { contextBridge } = require('electron')
+const { contextBridge, ipcRenderer } = require('electron')
 
 contextBridge.exposeInMainWorld('versions', {
     node: () => process.versions.node,
     chrome: () => process.versions.chrome,
     electron: () => process.versions.electron,
+    ping: () => ipcRenderer.invoke('ping'),
     // we can also expose variables, not just functions
 })