add embedded-io changelog entry

Author: almindor

CHANGELOG.md

@@ -7,6 +7,9 @@ and this project adheres to [Semantic Versioning](http://semver.org/).
 
 ## [Unreleased]
 
+### Added
+- Added `embedded-io` dependency to fill in basic traits for `embedded-hal` version `1.0`
+
 ### Changed
 - Use `portable-atomic` to allow builds on `riscv32imc-unknown-none-elf`` targets when needed
 - Update `embedded-hal` version to `1.0` changing `delay`, `spi`, `i2c`, `gpio` and `pwm` modules to match