Merge pull request #145 from AbdouMoumen/patch-1

Fixed typo in usage.md

Author: malte-wessel

docs/usage.md

@@ -81,7 +81,7 @@ class App extends Component {
 
 ## Auto-height
 
-You can active auto-height by setting the `autoHeight` property.
+You can activate auto-height by setting the `autoHeight` property.
 ```javascript
 import { Scrollbars } from 'react-custom-scrollbars';