Snippet format update

To match the starter (for the migration)

snippets/pull.md

@@ -1,4 +1,7 @@
-### pull
+---
+title: pull
+tags: array,intermediate
+---
 
 Mutates the original array to filter out the values specified.
 
@@ -19,4 +22,4 @@ const pull = (arr, ...args) => {
 ```js
 let myArray = ['a', 'b', 'c', 'a', 'b', 'c'];
 pull(myArray, 'a', 'c'); // myArray = [ 'b', 'b' ]
-```
+```