Added async function chain

snippets/chain-async-functions.md

@@ -0,0 +1,15 @@
+### Chain asynchronous functions
+
+Loop through an array of functions containing asynchronous events, calling `next` when each asynchronous event has completed.
+
+```js
+const chainAsync = fns => {
+	let curr = 0; const next = () => fns[curr++](next); next()
+}
+chainAsync([
+	next => { console.log('This happens at 0 seconds'); setTimeout(next, 1000) },
+	next => { console.log('This happens at 1 second'); setTimeout(next, 1000) },
+	next => { console.log('This happens at 2 seconds'); setTimeout(next, 1000) },
+	next => { console.log('Done at 3 seconds!') }
+])
+```