Update CHANGELOG

CHANGELOG.md

@@ -4,6 +4,14 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/).
 
 ## [Unreleased]
+### For Users
+#### Added
+- Automatically return from USB storage mode after the host (= your computer)
+  ejects the device.
+
+### Internals
+#### Changed
+- Restructured `epicardium/modules` into more sensible subdirectories.
 
 
 ## [v1.17] - 2021-04-04 - [R2R Rocket]