SASS compilation variable conventions update, focusing on basic colors, baseline variable usage for padding and margins, ui-depth extends, along with other small fixes. The intent with this is to not have any user-facing impact, and instead move us closer toward having files that use our newer sass conventions.

LMS/Accounts: Converts many class-based Sass archetype-focused @extends to use Sass placeholder syntax

Bourbon's box-shadow mixin has been deprecated, and they recommend to use the
official spec.

adds pressrelease page, breaks about content into seperate pages, imporvoves some visual elements of about and jobs pages

adds banner images to and refines header on find courses pages, various visual tweeks and imporvements

redesigns course item on home page and find courses page, refactors its implimentation and makes vrious other design improvements