Add a project changelog

CHANGELOG.md

@@ -0,0 +1,14 @@
+# Changelog
+
+All notable changes to this project will be documented in this file.
+
+The format is based on [Keep a Changelog](http://keepachangelog.com/en/1.0.0/)
+and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.html).
+
+## [Unreleased]
+
+## 1.0.0 - 2020-01-01
+
+- Initial versioned release.
+
+[Unreleased]: https://github.com/minetest-mods/gauges/compare/v1.0.0...HEAD

README.md

@@ -60,7 +60,9 @@ on that line.
 
 ## Version compatibility
 
-Gauges requires Minetest 5.0.0 or newer to work as expected.
+Gauges is currently primarily tested with Minetest 5.1.0. It may or may not work
+with newer or older versions. Issues arising in versions older than 5.0.0
+will generally not be fixed.
 
 ## License