Update changelog

Author: FelonEkonom

CHANGELOG.md

@@ -1,5 +1,8 @@
 # Changelog
 
+## 1.1.0-rc1
+ * Implement `handle_spec_setup_completed/3` and `handle_spec_playing` in Bins and Pipelines. [#801](github.com/membraneframework/membrane_core/pull/801)
+
 ## 1.1.0-rc0
  * Deprecate `handle_spec_started/3` callback in Bins and Pipelines. [#708](https://github.com/membraneframework/membrane_core/pull/708)
  * Handle buffers from input pads having `flow_control: :auto` only if demand on all output pads having `flow_control: :auto` is positive. [#693](https://github.com/membraneframework/membrane_core/pull/693)