Allow to import CSS from node_modules

[haggen]

Any particular reason we're excluding CSS loader from node_modules?

https://github.com/netlify-templates/victor-hugo/blob/master/webpack.common.js#L32-L36

This way I'm unable to import CSS packages from my index.js. I understand I could still import them from my CSS files but I find this indirect chain of imports harder to reason -- this import that that import that other thing.

Would we run into any issues by removing this exclude rule? Thanks in advance.