Apply new format to snippets and template

snippets/head.md

@@ -5,7 +5,7 @@ tags: array,beginner
 
 Returns the head of a list.
 
-Check if `arr` is truthy and has a `length` property, use `arr[0]` if possible to return the first element, otherwise return `undefined`.
+- Check if `arr` is truthy and has a `length` property, use `arr[0]` if possible to return the first element, otherwise return `undefined`.
 
 ```js
 const head = arr => (arr && arr.length ? arr[0] : undefined);