Snippet format update

To match the starter (for the migration)

snippets/merge.md

@@ -1,4 +1,7 @@
-### merge
+---
+title: merge
+tags: object,array,intermediate
+---
 
 Creates a new object from the combination of two or more objects.
 
@@ -28,4 +31,4 @@ const other = {
   c: 'foo'
 };
 merge(object, other); // { a: [ { x: 2 }, { y: 4 }, { z: 3 } ], b: [ 1, 2, 3 ], c: 'foo' }
-```
+```