@broskoski: Level up Scribe

This updates node modules and adds some [Scribe](https://github.com/guardian/scribe) plugin features. Most importantly allowing shift + enter to add breaks instead of full paragraphs and keyboard shortcuts like CMD + K for links.

![cap](https://cloud.githubusercontent.com/assets/555859/5404577/169beacc-8166-11e4-89a9-0b4e4c1da36f.gif)