iox-#590 Add release note entry for 'iceoryx_dust'

Signed-off-by: Simon Hoinkis <simon.hoinkis@apex.ai>

doc/website/release-notes/iceoryx-unreleased.md

@@ -66,6 +66,11 @@
 - Remove AtomicRelocatablePointer [\#1512](https://github.com/eclipse-iceoryx/iceoryx/issues/1512)
 - `SignalHandler` returns an `expected` in `registerSignalHandler` [\#1196](https://github.com/eclipse-iceoryx/iceoryx/issues/1196)
 - Remove the unused `PosixRights` struct [\#1556](https://github.com/eclipse-iceoryx/iceoryx/issues/1556)
+- Moved quality level 2 classes to new package `iceoryx_dust` [\#590](https://github.com/eclipse-iceoryx/iceoryx/issues/590)
+- Removed unused classes from `iceoryx_hoofs` [\#590](https://github.com/eclipse-iceoryx/iceoryx/issues/590)
+  - `cxx::PoorMansHeap`
+  - Other `internal` classes
+
 
 **Workflow:**