Add css autoprefixer to example

Author: Marek Rozmus

examples/package-lock.json

@@ -32,6 +32,7 @@
     "@babel/plugin-proposal-class-properties": "7.7.4",
     "@babel/preset-env": "7.7.6",
     "@babel/preset-react": "7.7.4",
+    "autoprefixer": "^9.7.3",
     "babel-eslint": "10.0.3",
     "babel-loader": "8.0.6",
     "css-loader": "3.3.0",
@@ -42,6 +43,7 @@
     "eslint-plugin-react-hooks": "2.3.0",
     "gh-pages": "2.1.1",
     "html-webpack-plugin": "3.2.0",
+    "postcss-loader": "^3.0.0",
     "prettier": "1.19.1",
     "style-loader": "1.0.1",
     "stylelint": "12.0.0",

examples/package.json

@@ -0,0 +1,3 @@
+module.exports = {
+  plugins: [require('autoprefixer')]
+};

examples/postcss.config.js

@@ -36,7 +36,8 @@ module.exports = {
             options: {
               modules: true
             }
-          }
+          },
+          { loader: 'postcss-loader' }
         ]
       }
     ]

examples/webpack.config.dev.js

@@ -36,7 +36,8 @@ module.exports = {
             options: {
               modules: true
             }
-          }
+          },
+          { loader: 'postcss-loader' }
         ]
       },
       {