Make webpack-dev-server work with react-router

webpack.config.js

@@ -26,5 +26,9 @@ module.exports = {
     ]
   },
 
-  plugins: [HtmlWebpackPluginConfig]
+  plugins: [HtmlWebpackPluginConfig],
+
+  devServer: {
+    historyApiFallback: true,
+  }
 }