adds debounce events page

Author: gingerchew

docs/javascript/debounce-events.md

@@ -0,0 +1,35 @@
+A debounced function is run after a defined delay.
+
+The function below has two parameters:
+
+-   passedFunction: the function normally given to eventListeners to run.
+    -   Can be an anonymous function e.g. function() {...}
+-   delay: amount of time to wait before firing function
+    -   Defaults to 200ms
+
+```js
+function debounced(passedFunction, delay = 200) {
+	let timerId;
+
+	//return function with arguments from passed function
+	return function(...args) {
+		//if timerid exists, clear it and start a new one
+		if (timerId) {
+			clearTimeout(timerId);
+		}
+
+		//since timerId is always unset, we must set it
+		timerId = setTimeout(() => {
+			//run passedFunction with ...args
+			passedFunction(...args);
+
+			//unset timerId
+			timerId = null;
+
+			//wait this long before you fire this function
+		}, delay);
+	};
+}
+```
+
+Based off of [this article](https://codeburst.io/throttling-and-debouncing-in-javascript-646d076d0a44)