Add note about nodeIntegration in README

[ci skip]

demos/electron/README.md

@@ -2,8 +2,10 @@
 
 This library is compatible with Electron and should just work out of the box.
 The demonstration uses Electron 9.0.5.  The library is added via `require` from
-the render process.  It can also be required from the main process, as shown in
-this demo to render a version string in the About dialog on OSX.
+the renderer process. Note that Electron now requires `nodeIntegration: true`
+in order to `require('XLSX')` in the renderer process.It can also be required
+from the main process, as shown in this demo to render a version string in the
+About dialog on OSX.
 
 The standard HTML5 `FileReader` techniques from the browser apply to Electron.
 This demo includes a drag-and-drop box as well as a file input box, mirroring

demos/electron/index.js

@@ -1,5 +1,5 @@
 /* xlsx.js (C) 2013-present SheetJS -- http://sheetjs.com */
-/*global Uint8Array, console */
+/* global Uint8Array, console */
 /* exported export_xlsx */
 /* eslint no-use-before-define:0 */
 var XLSX = require('xlsx');