v2.0.0

• added silent classes for all atomic classes for use in molecules and with @extend
• removed generation of -mobile classes; nuclide is mobile-first, so you should be using the base classes for your mobile/default styling, and overriding using -tablet and -desktop!
• added code comments prefixed with = for easily finding in generated output CSS
• removed molecular configuration, as molecules aren't part of core nuclide
• minor code comment and file naming improvements