chai: include ways to require chai

chai.md

@@ -3,10 +3,16 @@ title: Chai.js
 category: JavaScript libraries
 layout: 2017/sheet
 weight: -3
+version: chai v4.x
 ---
 
 ### Assert
 
+```js
+const { assert } = require('chai')
+```
+{: .-setup}
+
 ```js
 assert(val)
 assert.fail(actual, expected)
@@ -61,6 +67,11 @@ See: [Assert API](http://chaijs.com/api/assert/) _(chaijs.com)_
 
 ### BDD syntax
 
+```js
+const { expect } = require('chai')
+```
+{: .-setup}
+
 ```js
 expect(object)
   .to.equal(expected)