fix(easing): changed duration & easing to match ff (#58)

* fix(easing): changed duration & easing to match ff

* Sync with Prettier

Author: stipsan

src/index.ts

@@ -45,8 +45,8 @@ function smoothScroll(
   el,
   x,
   y,
-  duration = 300,
-  ease = t => 0.5 * (1 - Math.cos(Math.PI * t)),
+  duration = 450,
+  ease = t => 1 + --t * t * t * t * t,
   cb
 ) {
   let scrollable