Update snippet descriptions

snippets/initial.md

@@ -5,12 +5,12 @@ tags: array,beginner
 
 Returns all the elements of an array except the last one.
 
-- Use `arr.slice(0,-1)` to return all but the last element of the array.
+- Use `Array.prototype.slice(0,-1)` to return all but the last element of the array.
 
 ```js
 const initial = arr => arr.slice(0, -1);
 ```
 
 ```js
-initial([1, 2, 3]); // [1,2]
+initial([1, 2, 3]); // [1, 2]
 ```