Ensure page reloads in history mode serve index.html

After the switch to CopyWebpackPlugin (#1176), historyAPIFallback had to be adjusted to still serve index.html from all catched paths correctly.
See: vuejs-templates/webpack#1176 (comment)

Author: LinusBorg

template/build/webpack.dev.conf.js

@@ -23,7 +23,11 @@ const devWebpackConfig = merge(baseWebpackConfig, {
   // these devServer options should be customized in /config/index.js
   devServer: {
     clientLogLevel: 'warning',
-    historyApiFallback: true,
+    historyApiFallback: {
+      rewrites: [
+        { from: /.*/, to: path.join(config.dev.assetsPublicPath, 'index.html') },
+      ],
+    },
     hot: true,
     contentBase: false, // since we use CopyWebpackPlugin.
     compress: true,