libpldm: Add a changelog

The changelog is based around the expectations set out in "Keep a
Changelog":

https://keepachangelog.com/en/1.0.0/

Through review I will set the expectation that people modify
CHANGELOG.md in the patches changing the functionality in relevant ways.

When we need to commit to an API or ABI break we will first create a
tag before merging the breaking changes. This gives consumers of the
library sensible sequence points for migrating their code as we clean up
the library.

Signed-off-by: Andrew Jeffery <andrew@aj.id.au>
Change-Id: Ie361049829cfe7f1b962860bee6f7fe528f64e2a
diff --git a/CHANGELOG.md b/CHANGELOG.md
new file mode 100644
index 0000000..985cbfc
--- /dev/null
+++ b/CHANGELOG.md
@@ -0,0 +1,18 @@
+# Changelog
+
+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/),
+and this project adheres to
+[Semantic Versioning](https://semver.org/spec/v2.0.0.html).
+
+Change categories:
+
+- Added
+- Changed
+- Deprecated
+- Removed
+- Fixed
+- Security
+
+## [Unreleased]