Round out quote background (#560)

assets/scss/_base.scss

@@ -163,6 +163,8 @@ code {
   font-weight: 400;
   background-color: $alt-bg-color;
   color: $fg-color;
+  border-radius: 0.6rem;
+  padding: 0.3rem 0.6rem;
 }
 
 blockquote {