Implement SASS loader

[vvardges]

Install and use the required loaders:

npm install sass-loader node-sass webpack --save-dev
npm i -D postcss-loader
npm install postcss-cli autoprefixer
npm install postcss-cli precss

With minimal setup, your webpack config should include this rule or similar:

 ...
  {
    test: /\.(scss)$/,
    use: [{
      loader: 'style-loader', // inject CSS to page
    }, {
      loader: 'css-loader', // translates CSS into CommonJS modules
    }, {
      loader: 'postcss-loader', // Run post css actions
      options: {
        plugins: function () { // post css plugins, can be exported to postcss.config.js
          return [
            require('precss'),
            require('autoprefixer')
          ];
        }
      }
    }, {
      loader: 'sass-loader' // compiles SASS to CSS
    }]
  },
  ...