Snippet format update

To match the starter (for the migration)

snippets/untildify.md

@@ -1,4 +1,7 @@
-### untildify
+---
+title: untildify
+tags: node,string,beginner
+---
 
 Converts a tilde path to an absolute path.
 
@@ -10,4 +13,4 @@ const untildify = str => str.replace(/^~($|\/|\\)/, `${require('os').homedir()}$
 
 ```js
 untildify('~/node'); // '/Users/aUser/node'
-```
+```