Add link to chromecast icon assets

Author: Lindsay-Needs-Sleep

README.md

@@ -46,6 +46,10 @@ The "*Description" key strings will be used when asking the user for permission
 </platform>
 ```
 
+## Chromecast Assets  
+Here are some icons that may be useful in your app:  
+[chromecast-assets.zip](https://github.com/jellyfin/cordova-plugin-chromecast/wiki/chromecast-assets.zip)
+
 # Supports
 
 **Android** 4.4+ (may support lower, untested)