fix: adds missing breaking changes for 0.29 to changelog (#1370)

Author: alanshaw

CHANGELOG.md

@@ -53,10 +53,16 @@
 
 ### BREAKING CHANGES
 
-* pubsub.unsubscribe is now async and argument order for pubsub.subscribe has changed
-
-License: MIT
-Signed-off-by: Alan Shaw <alan@tableflip.io>
+1. Argument order for `pubsub.subscribe` has changed:
+    * Old: `pubsub.subscribe(topic, [options], handler, [callback]): Promise`
+    * New: `pubsub.subscribe(topic, handler, [options], [callback]): Promise`
+2. The `pubsub.unsubscribe` method has become async meaning that it now takes a callback or returns a promise:
+    * Old: `pubsub.unsubscribe(topic, handler): undefined`
+    * New: `pubsub.unsubscribe(topic, handler, [callback]): Promise`
+3. Property names on response objects for `ping` are now lowered:
+    * Old: `{ Success, Time, Text }`
+    * New: `{ success, time, text }`
+4. In the CLI, `jsipfs object data` no longer returns a newline after the end of the returned data