Merge pull request #38 from robyoung/add-changelog

Add CHANGELOG

Author: therealprof

CHANGELOG.md

@@ -0,0 +1,20 @@
+# Changelog
+
+All notable changes to this project will be documented in this file.
+
+The format is based on [Keep a Changelog](http://keepachangelog.com/)
+and this project adheres to [Semantic Versioning](http://semver.org/).
+
+## [Unreleased]
+
+### Added
+
+- Add `microbit::gpio` module with pins mapped to micro:bit names
+- Refactor `microbit::display` and `microbit::led` to accept `gpio::Pins`
+- Make probe-run the default runner
+- Rewrite `serial_port` as a macro
+
+### Fixed
+
+- Fix rustdoc warnings
+- Upgrade nrf51-hal to 0.12.1