chore(assets/css): remove smooth scrolling

Hijacking the browser's default behavior is a dick move. Edit your
preferences if you want smooth scrolling - and don't force your
preferences on anyone else.

assets/css/theme.css

@@ -18,7 +18,6 @@
  */
 
 :root {
-  scroll-behavior: smooth;
   --screen-size-small: 30em; /* breakpoint reference only */
 }
 @keyframes intro {