Invalid example of `webpack.config.js` in README

[shirohana]

Documentation Is:

• Missing
• Needed
• Confusing
• Not Sure?

Please Explain in Detail...

I found the webpack config example in README.md about line 1080 contains some abuses that can cause webpack reports an error:

Uncaught:
ValidationError: Invalid configuration object. Webpack has been initialized using a configuration object that does not match the API schema.
 - configuration.module.rules[0].use[3] has an unknown property 'test'. These properties are valid:
   object { ident?, loader?, options? }

Your Proposal for Changes

README.md#L1080

  **webpack.config.js**

  ```js
  module.exports = {
    module: {
      rules: [
        {
          // For CSS modules
          // For pure CSS - /\.css$/i,
          // For Sass/SCSS - /\.((c|sa|sc)ss)$/i,
          // For Less - /\.((c|le)ss)$/i,
          test: /\.((c|sa|sc)ss)$/i,
          use: [
            'style-loader',
            {
              loader: 'css-loader',
              options: {
                // Run `postcss-loader` on each CSS `@import`, do not forget that `sass-loader` compile non CSS `@import`'s into a single file
                // If you need run `sass-loader` and `postcss-loader` on each CSS `@import` please set it to `2`
                importLoaders: 1,
                // Automatically enable css modules for files satisfying `/\.module\.\w+$/i` RegExp.
                modules: { auto: true },
              },
            },
            {
              loader: 'postcss-loader',
              options: { plugins: () => [postcssPresetEnv({ stage: 0 })] },
            },
            // Can be `less-loader`
            // The `test` property should be `\.less/i`
            {
-             test: /\.s[ac]ss$/i,
+             // This `test` key is invalid in Rule#UseEntry, recommend to
+             // delete this line and comment together with `For CSS modules...` above
+             // test: /\.s[ac]ss$/i,
              loader: 'sass-loader',
            },
          ],
        },
        ...