Merge pull request 'Add ap and ActivityPub book' (#40) from evanp/delightful-activitypub-development:main into main

Reviewed-on: https://codeberg.org/fediverse/delightful-activitypub-development/pulls/40
Reviewed-by: Arnold Schrijver <circlebuilder@noreply.codeberg.org>

README.md

@@ -312,6 +312,8 @@ For an overview of known relays, see [Relay List, a regularly updated, sorted li
 
 * [**activity-streams-validator**](https://github.com/yuforium/activity-streams-validator) ([Fedi account](https://mastodon.social/@cpmoser)): Activity Streams validation for Typescript. `MIT, Typescript`
 
+* [**ap**](https://github.com/evanp/activitypub-book/tree/main/ap) - Command-line client for the ActivityPub API.
+
 * [**AP follow**](https://github.com/mwt/apfollow) - A remote follow tool to share links and buttons that allow people to follow you from their own ActivityPub instance `BSD-2-clause, PHP`
 
 * [**bridge**](https://source.joinmastodon.org/mastodon/bridge): A simple web app that helps you find your Twitter friends on the federated Mastodon network. It is also an example of how the Mastodon API can be used and the federated OAuth authorization flow. `AGPL-3.0, Ruby`
@@ -494,6 +496,8 @@ This category is for any code project related to the Fediverse. They need not be
 
 - [ActivityPub for Podcast Client Apps](https://minipub.dev/info/activitypub-for-podcast-apps/): Overview on how to implement cross-app comments for podcasts.
 
+- [ActivityPub: Programming for the Social Web](https://evanp.me/activitypub-book/): Book on ActivityPub from O'Reilly Media.
+
 ### ActivityPub server-to-server (S2S)
  
 - [Tutorial: A simple FediVerse Server](https://bovine.readthedocs.io/en/latest/tutorial_server.html): Building an ActivityPub Server to perform simple activities: post / follow / accept follow request. Tutorial also covers HTTP Signatures and WebFinger usage in bovine.