Consider using NODE_ENV=production as default on Netlify

[pixelastic]

Setting NODE_ENV as default on Netlify should make builds faster as it will not install the devDependencies.

norska is listed most of the time as a devDependencies and not a dependencies, but maybe it should move to a proper dep. Knowing if a SSG is a dev dep or a proper dep is a tough question.

One issue would be for libraries that have their website in a ./docs subfolder. Then norska should clearly be a devDependency as we don't want to release it. But in that case setting NODE_ENV to production would prevent deploying the website.

Overall I feel like I shouldn't make NODE_ENV a production value by default, yet

[pixelastic]

Actually set it as the default now, and norska should be moved to dependencies.

For websites with a subfolder ./docs with the webite, a better approach would actually be to make the repo a lerna-managed monorepo where each folder has its own package.json