Add motion.duration configuration (#846)

_config.yml

@@ -628,6 +628,7 @@ quicklink:
 motion:
   enable: true
   async: false
+  duration: 200
   transition:
     # All available transition variants: https://theme-next.js.org/animate/
     menu_item: fadeInDown

source/js/motion.js

@@ -17,7 +17,7 @@ NexT.motion.integrator = {
     if (!CONFIG.motion.async) this.queue = [this.queue.flat()];
     this.queue.forEach(sequence => {
       const timeline = window.anime.timeline({
-        duration: 200,
+        duration: CONFIG.motion?.duration ?? 200,
         easing  : 'linear'
       });
       sequence.forEach(item => {