rtic-sync: Update CHANGELOG

Author: datdenkikniet

rtic-sync/CHANGELOG.md

@@ -11,6 +11,10 @@ For each category, _Added_, _Changed_, _Fixed_ add new entries at the top!
 ### Changed
 
 - Add `loom` support.
+### Changed
+
+- Actually drop items left over in `Channel` on drop of `Channel`.
+- Allow for `split()`-ing a channel more than once without immediately panicking.
 - Don't force `Signal` import when using `make_signal` macro
 - Update `make_signal`'s documentation to match `make_channel`'s