Update README.md

README.md

@@ -3,6 +3,8 @@
 
 The ActivityPub protocol is a decentralized social networking protocol based upon the [ActivityStreams] 2.0 data format. It provides a client to server API for creating, updating and deleting content, as well as a federated server to server API for delivering notifications and content.
 
+* [https://activitypub.rocks/](https://activitypub.rocks/)
+* [https://www.w3.org/TR/activitypub/](https://www.w3.org/TR/activitypub/)
 
 ## Alternatives to other Mainstream services