test: include reftests previewer with docs website (#1799)

www/webpack.config.js

@@ -0,0 +1,20 @@
+const path = require('path');
+
+module.exports = {
+    mode: 'development',
+    target: 'web',
+    entry:  path.resolve(__dirname, './src/preview.ts'),
+    output: {
+        path: path.resolve(__dirname, './static/tests'),
+        filename: 'preview.js'
+    },
+    resolve: {
+        extensions: [".tsx", ".ts", ".js", ".json"]
+    },
+    module: {
+        rules: [
+            // all files with a '.ts' or '.tsx' extension will be handled by 'ts-loader'
+            { test: /\.tsx?$/, use: ["ts-loader"], exclude: /node_modules/ }
+        ]
+    }
+};