Snippet format update

To match the starter (for the migration)

snippets/pullBy.md

@@ -1,4 +1,7 @@
-### pullBy
+---
+title: pullBy
+tags: array,function,advanced
+---
 
 Mutates the original array to filter out the values specified, based on a given iterator function.
 
@@ -22,4 +25,4 @@ const pullBy = (arr, ...args) => {
 ```js
 var myArray = [{ x: 1 }, { x: 2 }, { x: 3 }, { x: 1 }];
 pullBy(myArray, [{ x: 1 }, { x: 3 }], o => o.x); // myArray = [{ x: 2 }]
-```
+```