Snippet format update

To match the starter (for the migration)

snippets/sortCharactersInString.md

@@ -1,4 +1,7 @@
-### sortCharactersInString
+---
+title: sortCharactersInString
+tags: string,beginner
+---
 
 Alphabetically sorts the characters in a string.
 
@@ -10,4 +13,4 @@ const sortCharactersInString = str => [...str].sort((a, b) => a.localeCompare(b)
 
 ```js
 sortCharactersInString('cabbage'); // 'aabbceg'
-```
+```