Add a link to the documentation.

Author: Sepand Parhami

README.md

@@ -2,6 +2,10 @@
 
 Some JavaScript animation helpers.
 
+## Links
+
+* [Documentation](https://ampproject.github.io/animations/)
+
 ## Image Transform
 
 Transforms an image from one position/size to another. In addition to scaling
@@ -37,4 +41,4 @@ To build, serve, and open a browser tab with the demos:
 
 ```shell
 npm run demo
-```
+```