Snippet format update

To match the starter (for the migration)

snippets/runAsync.md

@@ -1,4 +1,7 @@
-### runAsync
+---
+title: runAsync
+tags: browser,function,advanced,promise,url
+---
 
 Runs a function in a separate thread by using a [Web Worker](https://developer.mozilla.org/en-US/docs/Web/API/Web_Workers_API/Using_web_workers), allowing long running functions to not block the UI.
 
@@ -41,4 +44,4 @@ runAsync(longRunningFunction).then(console.log); // 209685000000
 runAsync(() => 10 ** 3).then(console.log); // 1000
 let outsideVariable = 50;
 runAsync(() => typeof outsideVariable).then(console.log); // 'undefined'
-```
+```