editorialise changelog

CHANGELOG.md

@@ -6,21 +6,15 @@
 
 [Full Changelog](https://github.com/ably/ably-go/compare/v1.2.11...v1.2.12)
 
-**Closed issues:**
-
-- Fix base url for go-pages [\#587](https://github.com/ably/ably-go/issues/587)
-- Clarification on client fallbacks/failures? [\#90](https://github.com/ably/ably-go/issues/90)
+This release adds a new experimental `RealtimeChannels.GetDerived` method which allows you to create custom realtime data feeds by selectively subscribing to receive only part of the data from the channel. See the [announcement post](https://pages.ably.com/subscription-filters-preview) for more information.
 
 **Merged pull requests:**
 
-- \[DSC-94\] add publish async method [\#596](https://github.com/ably/ably-go/pull/596) ([andydunstall](https://github.com/andydunstall))
-- channel: remove transient attach notice [\#595](https://github.com/ably/ably-go/pull/595) ([andydunstall](https://github.com/andydunstall))
-- Integration/subscription filters [\#594](https://github.com/ably/ably-go/pull/594) ([mschristensen](https://github.com/mschristensen))
-- Fix godocs base-url [\#591](https://github.com/ably/ably-go/pull/591) ([sacOO7](https://github.com/sacOO7))
-- add agents option [\#590](https://github.com/ably/ably-go/pull/590) ([andydunstall](https://github.com/andydunstall))
-- Run unit tests based on msgpack\_test\_fixtures [\#588](https://github.com/ably/ably-go/pull/588) ([amnonbc](https://github.com/amnonbc))
-- Go 1.20 is out, so we should test against it, and remove 1.18 [\#586](https://github.com/ably/ably-go/pull/586) ([amnonbc](https://github.com/amnonbc))
-- update the errors script so that it no longer generates constants from errors by mangling their descriptions. [\#585](https://github.com/ably/ably-go/pull/585) ([amnonbc](https://github.com/amnonbc))
+- Support Go 1.20, drop support for Go 1.18 [\#586](https://github.com/ably/ably-go/pull/586) ([amnonbc](https://github.com/amnonbc))
+- Add new GetDerived method to support subscription filters [\#594](https://github.com/ably/ably-go/pull/594) ([mschristensen](https://github.com/mschristensen))
+- Add new async publishing methods PublishAsync and PublishMultipleAsync [\#596](https://github.com/ably/ably-go/pull/596) ([andydunstall](https://github.com/andydunstall))
+- Fix docs for transient publishing [\#595](https://github.com/ably/ably-go/pull/595) ([andydunstall](https://github.com/andydunstall))
+- Add support for setting agents option [\#590](https://github.com/ably/ably-go/pull/590) ([andydunstall](https://github.com/andydunstall))
 
 ## [1.2.11](https://github.com/ably/ably-go/tree/v1.2.11)