Enable transforming of files in node_modules

[joshwnj]

If we want to require css from something in node_modules we need to use the global: true transform option (https://github.com/substack/node-browserify/#btransformtr-opts)

Example: the import-node-module case will fail by default, and will pass if we set transform options of { global: true }

[joshwnj]

Btw this doesn't cover if you want to composes: foo from "cool-styles/styles.css". I've got it mostly working locally but will wait for this one to merge before I add it.

[joshgillies]

Solid! 👍