Snippet format update

To match the starter (for the migration)

snippets/elementContains.md

@@ -1,4 +1,7 @@
-### elementContains
+---
+title: elementContains
+tags: browser,intermediate
+---
 
 Returns `true` if the `parent` element contains the `child` element, `false` otherwise.
 
@@ -11,4 +14,4 @@ const elementContains = (parent, child) => parent !== child && parent.contains(c
 ```js
 elementContains(document.querySelector('head'), document.querySelector('title')); // true
 elementContains(document.querySelector('body'), document.querySelector('body')); // false
-```
+```