readding node_modules due to npm best practice on website

see:
https://npmjs.org/doc/faq.html#Should-I-check-my-node_modules-folder-into-git

* Check node_modules into git for things you deploy, such as websites
and apps.
* Do not check node_modules into git for libraries and modules intended
to be reused.
* Use npm to manage dependencies in your dev environment, but not in
your deployment scripts.