LMS: Developer-centric Sass Area

This work adds in a known area for developers to add in new Sass, especially when needed and the current styling/UI patterns cannot support the features and bugs they are actively working on. Benefits of this include: 

* a known area in the cascade where styles will be inherited
* a designated area for developer use and design visual polishing and front end re-factoring (rather than hunting through the entire codebase).
* a location for developers to learn, request post-production support, receive feedback on any front end work, and ask questions of designers.