Snippet format update

To match the starter (for the migration)

snippets/isUpperCase.md

@@ -1,10 +1,12 @@
-### isUpperCase
+---
+title: isUpperCase
+tags: string,utility,beginner
+---
 
 Checks if a string is upper case.
 
 Convert the given string to upper case, using `String.prototype.toUpperCase()` and compare it to the original.
 
-
 ```js
 const isUpperCase = str => str === str.toUpperCase();
 ```
@@ -13,4 +15,4 @@ const isUpperCase = str => str === str.toUpperCase();
 isUpperCase('ABC'); // true
 isLowerCase('A3@$'); // true
 isLowerCase('aB4'); // false
-```
+```