Basecamp DarkMode

Unofficial DarkMode for Basecamp, since they don't provide one. The platform 'Basecamp' doesn't not provide Dark Mode. This extension injects a new CSS stylesheet (in simple terms that means changing/updating colors). This extension is the unofficial dark mode for Basecamp. There is no JavaScript involved whatsoever and just contains CSS. UPDATE 0.1.1 - 14 Feb 2021 - Fixed box shadow for project panels - Fixed box shadow for project avatars - Fixed box shadow for breadcrumbs