fix(lib/webpackConfig): __dirname on windows

Author: nklayman

lib/webpackConfig.js

@@ -1,6 +1,7 @@
 const fs = require('fs')
 const semver = require('semver')
 const { DefinePlugin } = require('webpack')
+const path = require('path')
 
 async function chainWebpack (api, pluginOptions, config) {
   const rendererProcessChain =
@@ -10,7 +11,7 @@ async function chainWebpack (api, pluginOptions, config) {
     ((devDependencies || {}).electron || '12.0.0').replace(/^\^/, ''),
     '12.0.0'
   )
-    ? '__dirname.replace("electron.asar/renderer", "app.asar")'
+    ? `__dirname.replace("electron.asar${path.sep()}renderer", "app.asar")`
     : 'require("electron").remote.app.getAppPath()'
   if (process.env.IS_ELECTRON) {
     if (pluginOptions.nodeIntegration) {