move devtool to main-menu

lib/main-menu.js

@@ -146,6 +146,16 @@ var view = {
       click: function () {
         BrowserWindow.getFocusedWindow().reload()
       }
+    },
+    {
+      label: 'Toggle Developer Tools',
+      accelerator: (function () {
+        if (process.platform === 'darwin') return 'Command+Alt+I'
+        else return 'Ctrl+Shift+I'
+      })(),
+      click: function () {
+        BrowserWindow.getFocusedWindow().toggleDevTools()
+      }
     }
   ]
 }