chore: updates CHANGELOG.md

Author: claymcleod

CHANGELOG.md

@@ -7,6 +7,7 @@ and this project adheres to [Semantic Versioning](http://semver.org/).
 
 ## [Unreleased]
 
+- `Timer`: adds `get_interrupt` to `Timer`
 - `gpio`: port and pin generics first, then mode,
   `PinMode` for modes instead of pins, `HL` trait, other cleanups
 - `flash`: add one-cycle delay of reading `BSY` bit after setting `STRT` bit to