update snippets 0-All

snippets/sleep.md

@@ -6,11 +6,12 @@ Delay executing part of an `async` function, by putting it to sleep, returning a
 
 ```js
 const sleep = ms => new Promise(resolve => setTimeout(resolve, ms));
-/*
+```
+
+```js
 async function sleepyWork() {
   console.log('I\'m going to sleep for 1 second.');
   await sleep(1000);
   console.log('I woke up after 1 second.');
 }
-*/
 ```