Fix: Copy static assets on build

Thanks @gutenye. Close styleguidist#403, styleguidist#489.

Author: sapegin

package-lock.json

@@ -38,6 +38,7 @@
     "clipboard-copy": "^1.2.0",
     "codemirror": "^5.26.0",
     "common-dir": "^1.0.1",
+    "copy-webpack-plugin": "^4.0.1",
     "css-loader": "^0.28.4",
     "doctrine": "^2.0.0",
     "es6-object-assign": "~1.1.0",

package.json

@@ -3,8 +3,9 @@
 const path = require('path');
 const webpack = require('webpack');
 const HtmlWebpackPlugin = require('html-webpack-plugin');
-const merge = require('webpack-merge');
 const CleanWebpackPlugin = require('clean-webpack-plugin');
+const CopyWebpackPlugin = require('copy-webpack-plugin');
+const merge = require('webpack-merge');
 const forEach = require('lodash/forEach');
 const hasJsonLoader = require('./utils/hasJsonLoader');
 const getWebpackVersion = require('./utils/getWebpackVersion');
@@ -78,6 +79,11 @@ module.exports = function(config, env) {
 					root: config.styleguideDir,
 					verbose: config.verbose,
 				}),
+				new CopyWebpackPlugin([
+					{
+						from: config.assetsDir,
+					},
+				]),
 			],
 		});
 		if (isWebpack1) {