update snippets 0-All

snippets/runPromisesInSeries.md

@@ -6,6 +6,9 @@ Use `Array.reduce()` to create a promise chain, where each promise returns the n
 
 ```js
 const runPromisesInSeries = ps => ps.reduce((p, next) => p.then(next), Promise.resolve());
-// const delay = (d) => new Promise(r => setTimeout(r, d))
-// runPromisesInSeries([() => delay(1000), () => delay(2000)]) -> executes each promise sequentially, taking a total of 3 seconds to complete
+```
+
+```js
+const delay = (d) => new Promise(r => setTimeout(r, d))
+runPromisesInSeries([() => delay(1000), () => delay(2000)]) -> //executes each promise sequentially, taking a total of 3 seconds to complete
 ```