support optimization splitChunks

[caiocaprio]

doubt, I can support 'optimization' to use the cache, something like:

optimization: { runtimeChunk: 'single', // runtimeChunk: false, // splitChunks: false, splitChunks: { cacheGroups: { 'public/js/vendors': { test: /[\\/]node_modules[\\/]/, name: 'public/js/vendors', enforce: true, chunks: 'all' } } } },

[thetumper]

See #180