Another American holiday, another chance to release some new things for PaperCSS!

• Update colors for better contrast and dark mode support (thanks @Famaxis for getting the ball rolling in #251)
• Fix default font import to include the recommended font-display: swap (thanks @marvelefe in #266)
• Fix modals to show over navbars (thanks @mef in #270)
• Fix Collapsible so that inputs can be displayed (thanks @mef in #277)
• Fix Sass color unit deprecation (thanks @almibarss in #282)