Added a simply debounce util to avoid using throttle plugins

assets/scripts/utils/debounce.js

@@ -0,0 +1,15 @@
+export default function(func, wait, immediate) {
+    let timeout;
+    return function() {
+        const context = this;
+        const args = arguments;
+        const later = function() {
+            timeout = null;
+            if (!immediate) func.apply(context, args);
+        };
+        const callNow = immediate && !timeout;
+        clearTimeout(timeout);
+        timeout = setTimeout(later, wait);
+        if (callNow) func.apply(context, args);
+    };
+}