added example for spread

Author: sgaurav

let.js

@@ -1,5 +1,5 @@
 /**
-  * let desclares a block scope local variable. let has been in Firefox for a 
+  * let declares a block scope local variable. let has been in Firefox for a 
   * long time and is now a part of ES6.
   * IMPORTANT: If outside any block, let is scoped globally else will be scoped
   * to nearest enclosing block.

spread.js

@@ -0,0 +1,11 @@
+/**
+  * spread allows you to pass each element of an array as a parameter.
+  */
+
+var list = [1, 2, 3, 4];
+
+function foo(i, j, k, l){
+    return i*j*k*l;
+}
+
+foo(...list); // 24