fix: slow recompile time (facebook#9911)

fixes facebook#9886

Author: FezVrasta

packages/react-scripts/config/webpack.config.js

@@ -752,6 +752,7 @@ module.exports = function (webpackEnv) {
         formatter: require.resolve('react-dev-utils/eslintFormatter'),
         eslintPath: require.resolve('eslint'),
         context: paths.appSrc,
+        cache: true,
         // ESLint class options
         cwd: paths.appPath,
         resolvePluginsRelativeTo: __dirname,