Snippet format update

To match the starter (for the migration)

snippets/size.md

@@ -1,4 +1,7 @@
-### size
+---
+title: size
+tags: object,array,string,intermediate
+---
 
 Get size of arrays, objects or strings.
 
@@ -24,4 +27,4 @@ const size = val =>
 size([1, 2, 3, 4, 5]); // 5
 size('size'); // 4
 size({ one: 1, two: 2, three: 3 }); // 3
-```
+```