add yarn (animate-css#865)

ahmetozantekin · eltonmesquita · commit 6fa759b7c2db · 2018-10-13T12:04:06.000-03:00
diff --git a/README.md b/README.md
@@ -18,6 +18,13 @@ or you can install via npm:
 $ npm install animate.css --save
 ```
 
+or you can install via yarn:
+
+```bash
+$ yarn add animate.css
+```
+
+
 ## Basic Usage
 
 1.  Include the stylesheet on your document's `<head>`
