Updates docs js function

docs/index.html

@@ -1123,12 +1123,10 @@ element.style.setProperty('--animate-duration', '0.5s');
     // When the animation ends, we clean the classes and resolve the Promise
     function handleAnimationEnd() {
       node.classList.remove(`${prefix}animated`, animationName);
-      node.removeEventListener('animationend', handleAnimationEnd);
-
       resolve('Animation ended');
     }
 
-    node.addEventListener('animationend', handleAnimationEnd);
+    node.addEventListener('animationend', handleAnimationEnd, {once: true});
   });
 </code></pre>
 <p>And use it like this:</p>

docsSource/sections/04-javascript.md

@@ -37,12 +37,12 @@ const animateCSS = (element, animation, prefix = 'animate__') =>
     node.classList.add(`${prefix}animated`, animationName);
 
     // When the animation ends, we clean the classes and resolve the Promise
-    handleAnimationEnd = () => {
+    function handleAnimationEnd() {
       node.classList.remove(`${prefix}animated`, animationName);
       resolve('Animation ended');
     }
 
-    node.addEventListener('animationend', handleAnimationEnd, {once : true});
+    node.addEventListener('animationend', handleAnimationEnd, {once: true});
   });
 ```